Expanding the IBM 5161 expansion unit 

Hehehe ... indeed it is ;) it’s definitely not an XT class certified table .... will have a new dedicated area with bigger , better storage and equipment in a couple of months time.

Bolling Holt hehe .... cool ... make sure to subscribe as I’ll be having lots more IBM related content here.

@@RetroSpector78 I already have :)

They both are not that common indeed. I also learned about these 2 last year and I have them both now.

@@GuybrushThriftweed I'm going to need another house and another job then because I keep discovering "new" things I want! 😂😂

@@BollingHolt yeah it's like a virus. I have around 50 systems (probably more) now and I need to dial it down a bit. My other hobby needs funds too :p

Really appreciate the kind words ! Looking forward to bringing some more cool content this year. Glad you are enjoying it.

Cool glad you enjoyed it. It’s a thin line cause you can easily bore people to death with it :) will probably make a more indepth video on it (also putting an AT class machine in the mix). Hope I won’t be boring too many people with this video ... was nice to be able to add all of this stuff in the pc and expansion unit.

Yeah that one is definitely coming ! Looking forward to creating that. Arduino style hardware development using gwbasic on an IBM pc :)

Glad you enjoyed it !

Thanks a lot ... really appreciate it !

True ... wanted to do this by the book :) thinking about going to do a separate video on conflicts and “cheats” like this. If you have more feel free to contact me :)

Afaik game 688 Attack Sub (if I forgot it correctly) is able to use a printer. And it has music too 😁

No never ... self-thought English speaking Belgian citizen that missed the subtlety’s between 3 and tree :)

@@RetroSpector78 I see. Well, you're in good company with that "tree" pronunciation regardless. :) From here en.wikipedia.org/wiki/Hiberno-English : "The phonemes /ð/ (as in the) and /θ/ (as in thin) are pronounced uniquely in most Hiberno-English. /ð/ is pronounced as [d] or [d̪], depending on specific dialect; and /θ/ is pronounced as [t] or [t̪]."

Yep, aware of the V20 but don't have one here ... going to look into the different integrated development environments that runs on this type of system. GWBasic would be time-period correct but the IDE is well .... very very basic :)

It is a pretty cool and capable machine now while at its core still an 8088 XT .... not the fastest machine to try all these hardware combinations on :)

I have an IBM ega card (and also 8 bit ibm vga card) lying here from a friend) that I’ll feature soon, but not on this ibm pc.... would be a bit overkill. Will save it for my IBM AT I think :)

Hehe ... so perhaps I do need to make a part 3 :) Thx for the info ... will look into that.

Is not hard. Remove the resisters on the one in the middle of the chain.

Didn't use ms-dos 2.0. The 10MB hard drive came with ibm dos 2.0 but because that cannot do anything with the xt-ide card I ended up booting msdos 6.22. I think 3.3 would have also worked.

@@RetroSpector78 Yes, I see now! Missed the 6,22 part 😳 I have a great Idea, can you connect some old X10 Home Domotica stuff from the 80ies like LGR did :-)

Dunno yet ... will need to checkout that video ... don’t wanna just copy something :) will give it my own twist

@@RetroSpector78 Yes its must be you own project. However its cool to let your setup do something we can still use today, X10 is perfect for that. What do you think, Will this software run ? www.ebay.com/itm/X-10-Home-Automation-System-Interface-With-Software-And-Connecting-Cable-New-X10/143429370423?hash=item21650e8237:g:auMAAOSwnbZYDYYz

@@RetroSpector78 p.s check this: www.investtech.com/nl/market.php?CompanyID=99400001

Thanks a lot .... really glad you enjou the videos ... Have boxes full of floppies and I usually take backups from these old xt hard drives. have it from there... but should not be that hard to find on the internet I think.

The compaq portable also looks like a fun machine. I am not that good with portables :) have a couple of old portables but really bad at fixing them. Friend of mine collects really old laptops and is really good at fixing them so he already helped me out with my 2 broken thinkpads.

Out of curiosity, how did you find my channel on youtube ? Always wonder how people end up finding smaller channels

@@RetroSpector78 I think it came as recommendation. I follow Adrian Black, the 8 bit guy, Jan beta, LGR among other retro related channels. I hope to be able to upload my 1st video very soon.

Hope you enjoyed the video ... got lots of other stuff also so if you feel like binge watching the channel feel free :)

Yeah, but I do like to keep things somewhat period correct :) But would be a fun experiment. Not sure if the mitsumi driver would work on an xt class machine.

look at sound card CD-ROM connectors - that is one brilliant ground pin row reuse between flipped Mitsumi and Sony connectors :)

You are limited because it is part of the core XT design. Only 1 Programmable Interrupt Controller on the mainboard and only 8 bit ISA slots to expose them to the expansion cards. (the additional IRQs that you get on an AT based system are in the 16 bit part of the ISA slot, so not available on an XT machine. There are lots of expansion cards that don't need an IRQ, and because the XT doesn't do a whole lot of multitasking you can cheat a bit and re-use some IRQs (ex: IRQ 7 from the LPT1 port can be used by another expansion card).

I was kind of surprised you didn't reuse IRQ7 for the sound card as was the norm.

Thank you sir ... hope you enjoyed the show.

@@RetroSpector78 Oh yes! As a matter of fact, I have enjoyed every single one of your shows after I had discovered your channel. You are doing an amazing job! Thanks!

Surprised that this would be so difficult to find. Pretty sure I’ve seen copies floating around the net.

Found it after some more googeling.

Not a whole lot of graphics environments that would work on this thing I think ... but will do some investigation ... Will probably do 1 more video on it cause then she will need to go and make room for some other projects.

@@RetroSpector78 She needs to go???!!!!!

@@RetroSpector78 GEM and GEOS should work on that beauty.

@@RetroSpector78 GEOS should work fine. Remember, they also did it on the C64.

btw you get a sub. this was a great video.

Thanks a lot ! Glad you enjoyed it !

Thank you for referencing _“STEINS;GATE”,_ an Anime I hadn't heard of before. I just binged all 25 episodes and it was a lot of fun. I particularly liked how they made retro-computing seem vastly important. *"If* *only* *we* *had* *an* *IBM* *5100,* *we* *could* *save* *the* *world!"* Fun fact I just noticed: if you use the New York Times archive (called "The Times Machine") and look up the September 10, 1975 issue, page 75, you'll see a picture of a man and a woman with an IBM 5100. The woman is using the computer, but the man is standing behind it pouring liquid into beakers like a mad scientist. Both are wearing lab coats. If you've seen _STEINS;GATE,_ it's pretty obvious who the two people are. By the way, the show never explains why its title has a semicolon where grammatically an apostrophe should be. My theory is that they used a semicolon because the IBM 5100 keyboard actually lacks an apostrophe (see for yourself in the picture on Wikipedia).

The XT machine only has half of the IRQs compared to an AT class system, and on both class of machines 2 are already in use.

@@RetroSpector78 I figured something like that. Thanks!

Would need to check ... next time I’ll make sure to invite someone from the Guinness Book of Records :)

@@RetroSpector78 Hehehe...

Need to look into that. Cause the 5150 was able to work with my xt ide card so I assumed the bios was more up to date. My other 5150 (albeit with a 16-64kb board) and older bios (not supporting xt ide) did work with 640kb ram.

@@RetroSpector78 Interesting.... Yeah, I had the same issues with my 256k 5150, 576 was it. I never bothered updating its bios though before I let my friend play about with it.. And all he did was mod the motherboard to put 512kb on board, and he left it at that. As that was enough for his rom burner. Until I go looking for the information again, I am only going to say I am about 75% sure a bios update fixes it.. lol

wishus knight will let you know for sure in a future video :)

Interrupt exhaustion..The expansion units are so rare that it would be really hard to get two working units in the same room 🤣

@@brentboswell1294 Lol, I know... Would be super interesting to see though

Sure .. drop me a mail (about section on my channel)

@@RetroSpector78 Done, in french as you are from belgium. Good to see another retro PC Fan not far from me (France)

Pentium systems are easy to come by here, and don’t tend to break as much as these old xt’s :) love the iomega zip drives. Use them a lot on xt machines also as a (slow) removable external hard drive.

A lot of people do :)

I'm using them too right now on my main Windows 10 machine!

I would have also thought that, but had the impression it only worked with the drivers loaded .... will recheck soon.

@@RetroSpector78 yes it does :) I noticed it with Comannder Keen 4 :) the best thing is that you do not waste memory, and as we know the memory in XT is very little :)

@@RetroSpector78 here check my XT Bulgarian clone with Comannder Keen 4 running with music via SB clone :) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-28jmOYZ2uE0.html

Will get its dedicated video ... could not get the software to run (not enough memory)

Yeah like I said I was running out of useful cards at the end :( had a Genius hand scanner card but 576kb of ram apparently wasn’t enough to run the scanner software.

The 5150 only accepts 576 as usable. That is an inherent limit with its bios if I remember.

So many people are telling me. I think I missed that when doing some past research ... do you have a pointer on that somewhere ?

@@RetroSpector78 I found this from an IBM doc found online. "(#1209) 256Kb Memory Expansion Option Provides 256Kb of parity-checked random access memory on a 5-inch card. Access time of the memory on the 256Kb Memory Expansion Option card is 290ns and the cycle time is 840ns. This card can be installed in any full-feature slot on the 5150 System Unit. For the 5150, this feature can be installed instead of the 64/256Kb Memory Expansion Option with three 64Kb Memory Module Kits to add 256Kb to the 5150 at a lower cost and/or to be able to use a special-feature instead of a full-feature slot for the additional 256Kb. Limitations: This adapter cannot be installed in the 5161 unit. Maximum: One with one 64/256Kb Memory Expansion Option with 64Kb or 128Kb to provide 576Kb or 640Kb. Field Installation: Yes. Prerequisites: The system unit must be at its maximum memory for this feature to be installed. Customer Setup: Yes. " There is also this mentioned in the same document. "(#6052) IBM 4700 Personal Computer Financial Output Option (No Longer Available as of August 16, 1989) This option allows the attachment of a single Finance Printer from this list using DOS 2.1 or later: 4710 Receipt/Validations Printer 4715 Continuous Forms Printer 4720 Forms/Passbook Printer - Models 1, 2, 3, or 4 The adapter card handles the 4700 loop protocol and data stream to the devices. It supports a single device with one or two logical device addresses. It attaches only devices that adhere to the 4700 Universal Device Processor protocols. Each option contains the Financial Output adapter card, the Financial Output Cable, installation and problem determination procedures, diagnostic diskette, microcode diskette with device drivers and configuration customization, and a microcode users guide. For more information about finance output devices, see 4710, 4715, and 4720 in "Machine" section. Prerequisite: An IBM Personal Computer with 256Kb on system board. Maximum: One. Limitations: The adapter must be installed in the system unit and not in a Expansion Unit. With this adapter installed memory is limited to 576Kb. " www-01.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_sm/0/872/ENUS5150/index.html&request_locale=en Seems like it can only accept memory expansions of limited sizes. And I wonder how that card (and mine for that matter) handled the addressing of memory blocks. What it looks like they are saying is you can have one expansion card of 256k and then a second for 64 or 128... So there may be a way to configure the card into giving the computer different block sizes? I am not sure if I am making any sense here, lol.

@@RetroSpector78 More from that document. "(#1003) 64Kb Memory Module Kit (No Longer Available as of January 24, 1989) Provides a 64Kb increment of parity-checked random access memory which may be plugged into sockets on the 5150 system board (Models 104, 114, 164, 174, X14, X64, X74 only) or the 64/256Kb Memory Expansion Option (#1013). The 64Kb Memory Module Kits are sold as small, plug-in circuits with instructions for user installation. Maximum: Up to three 64Kb Memory Module Kit increments may be customer installed on the system board, to provide an additional 192Kb of memory. The 64/256Kb Memory Expansion Option provides 64Kb of memory as standard. Up to three 64Kb Memory Module Kit increments may be customer-installed on a 64/256Kb Memory Expansion Option, to provide an additional 192Kb of memory. Field Installation: Yes. Prerequisites: Available sockets on the 5150 system board or available sockets on a 64/256Kb Memory Expansion Option. Customer Setup: Yes. (#1013) 64/256Kb Memory Expansion Option (No Longer Available as of January 24, 1989) Increments system memory by 64Kb (65,536 bytes) and is easily expandable to 256Kb by plugging in additional increments of 64Kb with 64Kb Memory Module Kits (#1003). The 64/256Kb Memory Expansion Option is packaged as a circuit card designed to plug into one of the 5150's five system expansion slots. Technical Information: Random access memory -- starting address is set by switches -- 250ns access time -- 410ns memory cycle time -- parity checking -- sockets for expansion to 256Kb. Limitations: The 5150 supports a maximum addressable memory of 640K bytes. The combination of the memory installed on the system board, and any installed 64/256Kb Memory Expansion Options, and 64Kb Memory Module Kits must not exceed a total of 640Kb of memory. The 64/256Kb Memory Expansion Option must be installed in the 5150 System Unit and not in a 5161 Expansion Unit. Maximum: A maximum of two 64/256Kb Memory Expansion Options may be installed in a 5150. Field Installation: Yes. Prerequisites: The system board must have 256Kb of memory installed (Models 104, 164, 176 only) before adding any additional memory via memory expansion options. An available system expansion slot is required for each 64/256Kb Memory Expansion Option. Customer Setup: Yes. "

Page 13 of this guide also has dip switch settings for installed ram. Not sure if this will help or not. I admit I don't recall ever futzing around with the switches on mine other than to change the video setting to color.... www.nj7p.org/Computers/IBM%20PC/work/OriginalPCReference.pdf

A cut scene would make the 30 minutes slog through the SoundBlaster install program more livable. Unless the programmers decided, for the sake of accuracy, it should actually take 30 minutes and be unskippable...

haha .... inderdaad ...... dude I promise you I will spend the next days / weeks / months practicing this in front of the mirror till I get it right. I tried soooooo hard to get it right this time :)

Huge thumbs up for trying to be a better video presenter!

How IBM squandered almost half of the 1 MB address space of the 8088 on the BIOS and I/O space is beyond me...The Tandy 2000 could address 768k of RAM!

@@brentboswell1294 and worse the palced it ABOVE the main memory had they put it below that the whole 640k barrier would never have existed

That was 10 times the RAM of most systems of the era. And RAM was over $8,500 a megabyte. Not many could afford even 640k.

Thanks a lot ... appreciate every sub and every view !

How is that better?

Thank you for that corrective statement. I was aware of it but also understand how my pronunciation of the "h" in that context could lead to some confusion :) Thank you for noticing and making it clear ! Hope you enjoyed the video !

But can you run fuck off?

That was quick .... Good job sir !

If you’ve got ideas for a final part 3 let me know ... the hard drive was acting up towards the end (like it was acting up when you brought it in :)

No you can't have it :p Guess I will need to store it and never use it again to save the HD from dying!!!!

Lord Cuntard if you’re just gonna store it and not use it you can just as well store a dead one :) but seriously ... was making that metallic sound towards the end again and didn’t boot from it last time I tried. Will try a LLF. Luckily I have a backup of the data :)

@@RetroSpector78 Yup that noise didn't sound healthy. Might need to go down the xt ide path. And it will have a lot of company from my other stored machines :)

We need to stumble on a large batch of mfm drives some day. If I do I’ll make sure to get you some.