The repair wires you noticed on the motherboard are usually indicative of a design fix found on early revision logic boards. It's a common practice by manufacturers to run these wires over the surface until a future revision of the board incorporates the fix in the design. This likely means your working PS/2-30 is older than the first. You may be able to confirm with via serial numbers and/or date codes on the computer.
The ones with the white power switch are the model 30-286 machines. All the 8086 ones have red switches. I had one of these with a Sota 386si accelerator card.
That's not quite right, I have a 30-8086 with a white switch. I'd read that IBM rebranded switches from red (from the XT/AT days) to white in the early days of the PS/2 line. Some early Model 60's also come with red switches.
Checked both of my ps/2 model 30 8086. But there are a few huge differences between the white switch and red switch 8086 version. The white switch version comes with a 1.44mb disk drive, the red switch has a 720kb diskdrive. But the biggest difference is the mainboard. The white switch version has the memory and rom chips on the right side of the mainboard near the psu unit and the cpu near the front left of the pcb. The red switch version has the memory and rom chips on the front left of the pcb and the cpu on the middel right of the pcb near the psu. The white switch version has a shirt serial number 55-kk*** and the white switch version 55-********. The 720Kb floppy uses an edge connector to connect to the drive. The 1.44Mb version uses a modified 34 pin floppy connector.
The Model 30 286 has ISA slots as well... also has VGA graphics! I love mine. Memory SIMMS are upgradeable but are nonstandard... they can be modified.
About the HDD issue. Try low-level formatting it with official IBM Diagnostics disk. Many drives after sitting a while lose their calibration, and writing all new tracks helps (or even almost completely resolves) the bad blocks issue. Also, XT-IDE CF ISA hard disks (such as the Lo-tech XT-CF-lite sold at Texelec) pair with these computers well. I'm not sure how long the old proprietary IBM hard disk will work on mine, but I'll use it as long as it runs. Floppy drives are a common issue on these, and there are ways to mod the FDD cable on 286's, but TexElec sells plug-and-play adapters for the model 30 (8086) floppy drives so you can fit standard floppy drives on it. Many owners buy a cheap NEC V20 CPU off second hand market that provides a 50% speed boost for the original model 30's and model 25's. Great video!
As the machine has ISA slots you could replace the IBM hard disks with an XT-IDE card and either IDE drives, or a CF adapter. A friend of mine has the Model 30-286 and did exactly that, as his machine didn't have a hard disk.
My first PC, (hated the MCGA not being EGA compatible). Even with the 8086, if you insert a VGA and an Adlib to the isa ports, this machine is great for 80's and early 90's games and software.
gotta love IBM PS/2 machines! Replace the caps on the floppy, it should come back to life. Sadly, that hard drive is NORMAL for these machines. There is a special model of the XT-IDE for the 25/30 and that is the route everyone should take with these systems.
@@tstahlfsu Thanks; that's my nice side. For my naughty side, I recently chewed out an older gent because he had used the #DOScember label to push off-topic content. I guess I've been gatekeeping the hashtag, lol, and I guess that goes both ways. :-P
Ya as others have mentioned those wires were done after the board was etched to fix a design bug or flaw. Very common to see on the old boards from the 80's in general. Some have a snakes nest of wires to bodge fix the problem. You can try to do a low level format in the bios if the bios or IBM utilities have such a function.
I'm not sure if someone else mentioned it earlier in the comments, but you can get an adapter to use a standard floppy drive with the PS2. The floppy drive in the PS2 is notorious for cap failures. texelec.com/product/ibm-ps2-to-standard-floppy-adapter/
I've never seen one, but it makes sense that if they had a "Model 30 286" that they would have a "Model 30" that is not a 286. Cool find! I had a 30/286 myself, really high quality machine.
With those ISA slots, you have MANY different options for when those hard drives inevitably fail. You can use a modern and inexpensive XTIDE ISA card, or if you want retro, an 8-bit SCSI card (with BIOS) and SCSI hard drives. I went the SCSI route on my Model 25 (8086), 8-bit TMC SCSI card, and a 400MB Seagate SCSI drive. Initially my M25 had an ISA hard card (notoriously unreliable Plus drive) and dual floppies, but I removed one (bad) floppy and installed the SCSI hard drive in that bay. I also installed a network card in the other ISA slot (the M25 only has 2), I can run mTCP stack and get some cool features like FTP for file transfers, and NTP for setting the system clock from the internet, also has IRC, and even Telnet.
The SCSI solution isn't a bad idea. In fact I probably have one lying around somewhere. Fortunately the hard drive is still going. Unfortunately the floppy drive is not. And apparently on other PS/2's they used a different standard for the floppy again. Amazing that they went to so much trouble to make things non-standard, even between their own machines!
The lower machine must have been bought originally at a store in Austria. But I also noticed a sticker from Deutsche Bundespost in the manual, so I guess that, along with a German MS-DOS, means the computer was meant for sale in Austria, Germany, maybe also Switzerland.
4:43: "...that's a high-performance CMOS colour look-up table, whatever that is." The colour lookup functionality refers to the fact that the VGA (EDIT: and MCGA) would look up the values for each of its 256 (simultaneous displayable) colours in a palette [i.e. table] of 262,144 colours. More info here: en.wikipedia.org/wiki/RAMDAC#History and here: en.wikipedia.org/wiki/VGA#Color_palette
That's right. I explain this shortly after that point in the video. But the name they give it here sounds like fancy IBM-speak for RAMDAC. They also call the hard drive a "hard file" whatever that is.
@@PCRetroTech The CLUT moniker (currently) does make an appearance in that RAMDAC article, and there's also this: en.wikipedia.org/wiki/CLUT If you think IBM terminology is weird and insular, you must not have met Microsoft. I could be mistaken, but I think I recall that a hard file originally used to be some specific HD product, possibly a hard card, which would make hard file another genericised trademark too. I could be wrong though. Evidence for semi-obscure things that were a thing before the advent of the WWW is often harder to google.
Really nice comprehensive coverage of the Model 30, thank you. You've managed to make a nice amalgam of the two computers there. You could do future videos perhaps looking at a Sound Blaster or And Lib upgrade?
I upgraded mine model 30 8086 with a soundblaster 16 vibra 16 bit card. It will workin a 8 bit slot as a lot of early 16 bit cards do. Since the 16 bit part is mostly used for the cd rom.
When sears had them as demo units and I would create prodigy account and prodigy at the time had a cheap version of 3d graphics adventure via dialup. It was fun by crazy slow. I am tempted to buy the top model of that version which at the time at retail was just around $4,000 You could buy it today for under $500 now I think
Oh yeah, the good old days... If I remember correctly, within Budokan on the courtyard you could go down to the lower left edge (below the hall) and press 'b' or 'd' - and play an arkanoid-style minigame!
@PCRetroTech Wow, this brings back memories! My first PC was a Model 30 286, which I saved up for while in high school at 17 years old in 1988. I remember being the only kid who had a PC at home with VGA graphics, as everyone else I knew was still on 16 colours. Within 3 months of ownership I had worked out how to totally dismantle and reassemble the whole machine. It is what got me started in a career as a computer technician and retail sales from 1990 to 2015. I even played the same games you featured in the video - Budokan, Links and Thunderstrike (plus its follow up Stike II) - on my PS/2. But I must say, the 286 handled the games way better. Especially Thunderstrike was miles faster - to about double the frame rate in your video. I upgraded it with an OG Sound Blaster card and 2400 baud internal modem. Would you believe I even ran the machine as a local BBS for 2 years! (Yes on its tiny 20MB hard drive and all!) Sadly, by 1991 I had far outgrown my PS/2. So I sold it back to the same store I originally purchased it from. (Much to my disappointment these days, as I love to still have it!) However, get this, they payed me back close to the same amount of money as I had originally payed for it new! Being a true blue IBM machine meant it kept its value very well. That never happens these days. Anyway, the money I got back was enough for me to purchase hardware and build my own 486 clone. And the rest is history...
You were lucky to get a PC in 1988 with VGA. Our family still had an outdated Atari 800XL and even more outdated TI-99/4A at that time. In 1988 you wouldn't be able to find any games using 256 color VGA graphics. If a 1988 game had VGA capability, it usually displayed the same 16 colors as EGA, usually for machines that were equipped with MCGA (since MCGA could display 256 colors, but not EGA backwards compatible). Occasional games using VGA this early on did still display 16 colors, but a slightly different palette from EGA, like Airball. Dream Zone did use a VGA palette for nearly photo-realistic black and white scenes in the early part of the game (which you couldn't do in EGA) but it was still 16 colors. You had to wait until 1989 to find games using 256 color VGA like Mean Streets, 688 Attack Sub, Tongue of the Fatman, Face-Off. Budokan, etc. Deluxe Draw II did come out in 1988 and it was VGA capable, and you could create art using the 256 colors even in 1988.
@@Miler97487 You are totally right! I had to wait a bit before games used the full colours. But yes I did have a copy of Deluxe Paint (aquired from my school). Those games though, they bring back so many memories of wonderment. Budokan, Fatman and Mean Streets! Our school was fortunate enough to have a single PS/2 30 286 in the library for us to use during lunches. (20+ Apple IIs and IBM PCjrs were elsewhere in the nominated computer room for class learning.) Using and playing on the PS/2 made my mind up to get that exact same model. I wasn't totally aware that VGA would come into play until after I'd bought it. I just knew it was better than the 4 colour CGA on the PCjrs. Took me six months of hard work and bartering to save up. Plus my very kind Grandmother offering to double my earnings. 😉
I used to have this PC as a kid. You should try Star Control 1 - it looks and plays great. Also, Prince of Persia 1. The MCGA is also great for some of the early point-and-click adventures - they run with beautiful 256-color graphics and they don't really require much CPU power. Another advantage of the MCGA was that it supports the undocumented/tweaked CGA modes, so it has excellent CGA compatiblity, better than the EGA and the VGA. And the biggest drawback - it doesn't support any of the EGA modes. It was really frustrating to have to run games from the 1984-1986 period in ugly 4-colour CGA modes, because MCGA doesn't support EGA 320x200 with 16 colours (even though it supports 320x200 with 256 colours).
I believe the white switch models were the 286 variant, while the 8086 models all had red switches. I have two of these but the power supplies have issues. One note that if you are working on a drive, do not set it on top of the plastic. It's grounded and conductive! Lesson learned.
Nice overview of the PS/2 model 30. The PS/2 Model 30-286 has full VGA, if you ever come across one. The Model 25 all-in-one system is also MCGA. There is also an Epson clone that had MCGA (a fact I learned only this year!) Some software notes: Revenge of Defender is slow because it's building a 64K page in RAM and moving the entire page to A000, but because the programmer chose to render the page bottom to top for some reason, the move to A000 is slower than it needs to be. A-10 Tank Killer is slightly faster because it's only rendering and moving the top half of the screen. That said, the polygon rendering rate is impressively fast. BTW, did you notice the main ship in Thunderstrike is light-shaded? (Lambert shading) The light source is fixed (I don't think it rotates with the camera) but it's still a nice detail.
I actually didn't notice the Lambert shading. However, I recently saw the C=Bit 18 by Performers demo and they have shaded polyhedra which has my noodle fully baked. I simply don't know how they've done that on a C64. I have something new to aim for in 2021! P.S: I think they probably have 15s precomp to play with, but still!
@@JimLeonard Yeah, but it's not flat shading. The cost of just copying pixels from a lookup somewhere is already pretty high, let alone doing all the normal computations. I wonder just how fake it is. It looks amazing.
@@JimLeonard: "There is also an Epson clone that had MCGA (a fact I learned only this year!)" The Epson Ie "clones" the Model 30 so close that it is more than a coincidence. There is a planar functions control register that is mimicked exactly, including the same bit-order for each of the planar features. It seems that Epson was released to field their own model at some point after they designed the Model 30 for IBM. The Epson Ie did unify the MCGA controller into one newer chip - I would even bet that a fault of the MCGA gate array chip that was replaced with a different version for the Model 25 and 30 systems is fixed on the Epson Ie. I'm referencing ECA 023 (IBM's Engineering Change Announcement list) which seems to be the reason that IBM replaced the Model 30 "P-Planar" with the "Greenock planar", and the move from the Model 25 'Type 1' planar to the 'Type 2' - Second versions that had the 11F8028 gate array instead of the earlier 72X8300.
I have the MCGA bodge wire in one of my PS/2 model 30 computers, too. It's carrying the vsync signal, and it is just re-routed. The original trace is near the edge of the board and was likely prone to pick up noise or had a problem with reflections. They scratched the original trace close to the point the bodge wire attaches at the big gate array chip and also close to where the trace re-joins the net at the other end. About that scrolling shooter: VGA has some hardware support for scrolling a playfield with a score bar in the bottom staying at the same position (needs mode X instead of mode 19/13h though to be useful), whereas MCGA is just a stupid framebuffer, so every frame the game has to redraw 60 Kilobytes (as you explain later at 27:30, too). As the MCGA is (like the original IBM VGA) connected to the 8-bit system bus, and not to the 16 bit "local bus" (only RAM and processor go there), drawing 60 Kilobytes is quite slow.
Dark brown PCB too? Mine attaches to a solder pad just off the 72X8300 Gate Array chip (that was replaced by an 11F8028 on later planars) - @PCRetroTech has the bodge-wire going to the chip pin itself. Do you know what BIOS version yours is? Here is my latest kludgy video to toggle enabling the planar functions, including MCGA: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JmrKx7wHGLI.html
@@IBM_Museum I have looked into two PS/2 model 30s (Both non-286). The older one has the bodge wire, attached to the via next to the 72X8300 gate array. The trace continues to another via, but is scratched inbetween. This planar is green and BIOS chips 61X8937/61X8938 installed. Some component designators are missing is cramped areas. The newer PS/2 model 30 planar is a brown PCB, has no bodge wire, but has that connection re-routed. It has the new BIOS 61X8938/61X8940 instead. I don't know which label that gate array (the "video memory control gate array" in IBM speak) has on the newer board, and that board is currently not in my reach. PCB designators are printed in a seemingly bigger font, and at the same time there are no missing designators.
@@tw11tube: The MCGA Gate Array chip changed between the Model 30 early "P-Planar" and the later "Greenock planar" (components identified exactly the same, but some changed in position), and on the Model 25 between the 'Type 1' and 'Type 2' planars (fewer components moves, but an IBM 'ECA' specified a planar replacement for video errors caused by the 72X8300 Gate Array - there are no bodge-wires on3 either Model 25 planar). The underside of my Model 30 planar with the bodge-wire (and "Revision 0" BIOS) is marked in pen as '2/87' (the initial PS/2 release was in April 1987). Model 30 BIOS versions are listed here: ibmmuseum.com/BIOS/8530/Versions.txt - All are dumped in the same directory. See my channel for more Model 30 information. The "Hakemon Mike" channel is a friend that has also investigated MCGA.
Great video as always! Are the connections to the original drives functionally different to regular drives or are they just a non-standard connector? If functionally compatible then maybe it would be possible to design adapter pcb(s) to interface between the Model 30 style connectors and the connections on standard drives...
@@PCRetroTech The PS/2 Model 30 hard disk is a proprietary 8-bit XT-Attachment drive that is compatible to nothing else in the world (except for PS/2 Model 25 hard drives, as the Model 25 uses the same kind of drives). It's not just the connectors that differ, it's also a different command set.
My friend Anton fixed 2 of these floppy drives by replacing capacitors on them. There was also a potentiometer that he had to replace on one. I'd bet that you can revive these drives the way he did.
Well, actually even though this has a 8086 cpu, it is a bit faster then the once popular 8088 found in the original pc. So, it was in many ways an improvement. Just in a vastly proprietary way. The PS/2 model 30 was the educational model in that these had been targeted to the educational market. It's why it has such lower end hardware and ISA slots. Back then buying IBM was expensive. Still is.. anything IBM was costly like Apple. So like Apple IBM offered models aimed at saving certain sectors money. The model 25 if I recall is an AIO variant of this same computer.
The 8086 came out first. Later intel started to produce the 8088 as a cut down version of the 8086. With if i recall correctly a 8 bit databus instead of the 16 bit of the 8086.
The bad sectors may not necessarily mean the drives are imminently failing. Most drives of the time developed bad sectors even in the few years they were used, but scandisk would mark them and avoid using them. (Scandisk was usually scheduled weekly if not daily.) Overall you didn't seem to lose a lot of space from it. Granted, the extra few decades won't have helped but I say try use them for as long as possible if only for the nostalgia factor.
Unless you really want to hang on to those failing HDDs the XTIDE is an excellent storage solution for the model 30. It's a pity MCGA doesn't have EGA mode support, but that said, there are a lot of fun 80s CGA games to try, which don't always run correctly on faster hardware.
@@PCRetroTech PS: As you're doubtlessly aware, but maybe for the benefit of other RU-vidrs, the reason that famous organ piece is scarcely recognisable or at least doesn't sound its best is that PWM arpeggios rely on the mechanics of ye olde PC speaker, or specifically on the mechanical inertia between the magnet and diaphragm/coil, i.e. fast voltage changes occur before the moving membrane part has travelled all the way. Reproducing those sounds as they were meant to be heard heavily depends on the physical construction of the PC speaker, and most clone makers got it right by using exactly the same generic speaker. Why IBM felt they had to replace that with a piezo buzzer may well remain unclear. _Maybe they were disappointed they hadn't yet gotten to include MCA in this model and felt they had to mix things up somehow?_ /s Of course, by the time this thing came out, buying IBM wasn't just a downgrade in terms of sound: The Compaq Deskpro 386 was already on the market when the PS/2 was unveiled, and at least this incarnation of it was essentially still an XT-class machine. More related info: Jim's "IBM PC Sound Ramblings" at oldskool dot org and this Computer Chronicles episode: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-n81RKe-tu7Y.html
Check out spin rite to try and restore those hard drives. Maybe it supports those drives. Recent versions obviously include large drive support, but if the older drive support was dropped, I'd think acquiring an older version would help. Even the new versions run in conventional memory in real mode, so I suspect there's a high degree of backwards compatibility. But the tool can run a better surface scan than scandisk, by performing several reads to get the best one, then it'll flip the bit back and forth to try and restore the sector. And can even pull the raw analog signal from the drive head to try and process out what the level should be. It can often recover/restore bad sectors, if not recover the data and map bad, all before even the os and fat become involved. Had it remap a boot sector on my old quantum fireball back in the day, which is often a fatal failure.
@@PCRetroTech yes. Not entirely sure about backwards compatibility that far back, but like I said, the creator has kept it so it'll run in under 640k and in real time, so he's at least considering XTs.
MCGA was a wierd standard, with some strange choices made by IBM, no ega compatibility was a mistake.Late 80s saw a lot of 16 colour ega titles that would not work on MCGA except for a few that used 256 colour mode for MCA with an ega like palette. VGA obiously fixed all the issues bringning together mcga and ega
So you say that MCGA was introduced right in the 8086 Model 30? I'll have to dig up my motherboard cupboard. I don't have anything but the m/b, the PSU and the ISA-8 riser but with a SCSI card I could boot it. And what kind of video output does it have? Unfortunately I don't have anything but VGA 15-pin D-SUB for this kind of computers. If it's 9-pin I really don't know what I can do.
@@PCRetroTech - The Model 30 was produced first, I even have a theory that IBM contracted Seiko-Epson (the logo on all the planar chips) to do it. An Epson Equity Ie is an exact Model 30 clone - including MCGA - so it is limited to three systems with about six different planars (there were some slight variations on IBM's side). When you realize that there is a Seiko-Epson logo on four out of the five VGA chips used for PS/2s it becomes more interesting - and that one chip is the "silver-cap" 72X8287 used less commonly. There is still some detective work to be done three decades later. As you have discussed elsewhere "Hakemon Mike" understands MCGA very well - we're going to figure all this out!
@@IBM_Museum Yes, I had heard about the Seiko link. Would be great if someone from IBM were able to give details one day. Perhaps some old IBM (or Seiko) employee will eventually tell what happened.
You can connect a standard vga monitor to the 15 pin sub d monitor connector. But you will need to cut out 1 pin in the cable, since the mcga dsub connector has 1 blanked out pin. Mcga is a advanced cga mode, not a vga mode. The mcga chip in the model 30 8086 supports only cga, since it is a cga card. no support for ega, a vga card would have ega support. The model 30 286 does have full vga support. The 286 version also supports ega screen modes.
@@theseob Hm, so basically it gives a 15.something-kHz CGA signal through a 15-pin D-SUB connector? If so, I cross my fingers for my Samsung 214T that otherwise can perfectly sync with a C-64 on its composite or S-Video port.
Yes. One has to hack around with the CGA registers. In particular one needs to set the character height to 4 and then choose a character which is half the background colour and half the foreground colour. That gives you an effective resolution of 160x100.
@@PCRetroTech How do you avoid CGA text mode flicker/noise when updating the screen? Are you racing the beam? (Or do these later display adapters eliminate that old problem?) Edit: My question was answered in your CGA Rotozoom video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-cSxYljs5OxE.html
@@spatulasnout Good question. It turns out that the video RAM is dual ported on both the Amstrad and Model 30. Of course if you run this demo on an original IBM CGA card it produces a great deal of flicker.
@@PCRetroTech Whatever it is, it's something the system is capable of detecting because it actually gives me POST beeps corresponding to a graphics issue. I did get a working Model 55 and a working Model 30/286 out of the trip though.
@@MatroxMillennium: The MCGA video on the 8086-based Model 30 seems to be very sensitive to power loads - if you have the earlier "P-Planar" board, it likely has the 72X8300 Gate Array chip - If you have extras like a math co-processor or other items, temporarily remove them. Try heating the chip with a hairdryer. Or just swap in a VGA adapter able to run from an 8-bit connection.
@@IBM_Museum Yeah, I'll have to open it back up and take a look sometime. I do have a hot air rework station and was thinking about trying to reflow some of the chips to see if it made a difference.
ISA slots mean you can throw in a floppy controller card and either an XT-IDE controller or an MFM controller. You have all the same options as you would on a standard XT/XT clone.
@@PCRetroTech lol, good luck with the channel, I am sure you will get far with that attitude. Maybe consider that some of the people taking to time to post know what they are talking about.
I don't know what voltages and currents a floppy drive would need, but would it be possible to use another ISA slot, if one is available? Like, if there's some broken card, would it be possible to saw off the connector with a little of the board left, and solder wires to the traces that were for drawing power? (I have no idea if there's any hope with that to work in practice -- I haven't worked much with those things -- I just thought that there must be some power available from the ISA slots, so maybe that could be used -- in theory...)
@@enginerd80 I believe it is also possible to make an adapter from the existing connector to a molex plug for power, plus a standard floppy connector. I like to keep things original, so probably repairing the drive is my favourite option.
@@PCRetroTech There are relatively cheap adapters for the floppy drive to use standard PC ones which will include data and power (sadly none for the HDD, as it is not ATA rather some kind of EDSI). There tiny and won't take away much from the originality. TexElec has one for about $15, and there some free board designs on github. It's just a passive pinout adapter from boardedge to pinheader & power.
As far as I understand, ALL red-switch PS/2 30's are 8086, while most white switch 30's are 286. I heard (and have personally seen) very uncommon red switch 286's too. I believe the early 286's were all red switch models.
This is my understanding, but I hesitated to comment on it as repairing old machines is very common where I live, and one can easily go wrong if simply looking at the switch.
@@PCRetroTech Yeah I have never come upon a red switch 286 since the 90's. But I'm sure they exist, and people swear they've seen them, including myself. :D
Internally the model 30 286 uses a different power supply and motherboard connectors then a model 30 8086. I hav e 3 model 30’s. Two 8086’s one with a red power switch, and one with a white power switch. The model 30 286 also has a white switch. It also has a different cover. The model 30 with 8086 cpu has a white cover with a dark grey/brown bottom bezel and is closed using 4 screws. The model 30 286 has a all white cover and is closed with 2 screws on the front. No screws near the rear.
@@PCRetroTech And understandably so, considering it was a last ditch effort by Big Blue to corner the market. Shame they went that avenue, since now it makes the parts hard to come by. I wonder if someone's concocted some sort of CF/SD card solution on the drive front. And thanks! By the time I upgraded to a 486 the Model 50 was woefully inadequate in a lot of ways. Though in hindsight I wish I'd known then some of the things I know now: such as the fact that it could have run windows (which would have been more for "hey it works" than actually being useful since the Model 50 only had a 20 MB HD (and 286 CPU)), and that it was of course with a color monitor, capable of color graphics (by the looks of it Model 50 appears to be one of the first with actual VGA) - the monitor that went with this thing was an IBM model but it was monochrome "VGA", so it could do a significant number of shades of gray, but to see it running DOSShell or WordPerfect in color would have been awesome.
There's an interesting video on MCGA and its architecture: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-jCCaobFpKWc.html There's PS/2 Model 30 technical documentation and schematics linked in this video's description. The video itself also shows which Model 30 chips implement every part of MCGA's functionality. And the interesting part is that MCGA actually seems to be more of a CGA derivative than a scaled-down VGA.
That's some really fantastic information! That guy is quite a character too. I agree that MCGA is like a CGA derivative. I really think of it as 256 colour CGA. I have to admit to not realising there's only 64kb of memory on those things. Probably if I'd thought about it for more than a few seconds I would realise that it had to be that way. IBM wouldn't put 256kb of memory in and only use 64kb of it!
That works most of the time, however some people have reported exceptions. It's unclear whether these exceptions go right back to the factory or are due to retro collectors and sellers mixing and matching.
