VOGONS


List of open-source PC hardware projects

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Reply 100 of 128, by RayeR

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I just finished parity SIMM 72-pin design (just 2-layers to save money but pwr/gnd planes could be added in future if needed).
I plan to send a batch of PCBs to JLC until end of this month to get advantage of 2$ discount for 4L 50x50mm for PentiumMMX mobile interposer.

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Gigabyte GA-P67-DS3-B3, Core i7-2600K @4,5GHz, 8GB DDR3, 128GB SSD, GTX970(GF7900GT), SB Audigy + YMF724F + DreamBlaster combo + LPC2ISA

Reply 101 of 128, by zyga64

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A new version of BlueSCSI has just been released, based on the Raspberry PI Pico (much faster - up to 10MB/s read). The software is derived from the ZuluSCSI project.
https://bluescsi.com/v2

1) VLSI SCAMP /286@20 /4M /CL-GD5422 /CMI8330
2) i420EX /486DX33 /16M /TGUI9440 /GUS+ALS100+MT32PI
3) i430FX /K6-2@400 /64M /Rage Pro PCI /ES1370+YMF718
4) i440BX /P!!!750 /256M /MX440 /SBLive!
5) iB75 /3470s /4G /HD7750 /HDA

Reply 102 of 128, by RayeR

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I received my PCBs from JLCPCB and started assembly the SIMM module. At 1st test stage I soldered only 8 DRAMs of 12 and it works fine (memory tests passed, even it's only 2-layer design) but I found a mechanical problem. I didn't get aware of PCB thickness and now I see the original SIMM is 1.2mm thick PCB while I made all PCBs on JLC default thickness 1.6mm. The module fits into a socket but it's tight. Some sockets are relative OK some are very tight. I'm bit afraid of spring-pins to not deform them too much so I rather not left module in a socket for long time and pull it out. When I googled about this I found Alex. Groza article about his 30-pin SIMM and he catched at the same thing. If I would read his article (that I already had downloaded for offline reading) before I could order the proper PCB thickness...

So, never mind, the price for this PCBs was ~5,5$ and I use it for testing in my Alpha64 after I will solder the rest of DRAMs and set the ID bits. Then I will give another try in JLCPCB when there will be a chance or I will collect PCBs for a next batch...

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Gigabyte GA-P67-DS3-B3, Core i7-2600K @4,5GHz, 8GB DDR3, 128GB SSD, GTX970(GF7900GT), SB Audigy + YMF724F + DreamBlaster combo + LPC2ISA

Reply 103 of 128, by ALEKS

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Yes, I know. My first SIMMs in 1.6 mm thickness were a very frustrating experience for me as well. And exactly as you say, some of sockets do accept 1.6 mm PCBs but they look a bit stressed.
I re-did mine at JLCPCB in 1.2 mm, they work great and are a perfect fit for the SIMM sockets. On the downside, the black soldermask quality is not very good. The JLCPCB green one is better, similar to the purple soldermask from OSHPark.

4mx9-simm-120-pcba6.jpg

Good job on your SIMM design! Glad to hear it works on a dual-layer PCB.

Cheers,

TX486DLC / 40 MHz | 32 Mb RAM | 16-bit ISA Backplane | Tseng Labs ET4000/W32i 2 Mb | I/O Interface | Audio Interface | PC Speaker Driver | Signal View Interface
3.5" & 5.25" FDD | 4 x 512 Mb CF | HP 82341D Interface | Intel EtherExpress 16

Reply 104 of 128, by RayeR

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I soldered the rest of DRAM chips (I had to borrow them from another working parity module because I don't have any other donor now) and it works fine in Alpha64. So when possible I will let manufacture them again with right thickness.
I'm not a fan of black or white opaque solder mask, I like visible traces. So I usually keep default green mask, only once I made red.

Gigabyte GA-P67-DS3-B3, Core i7-2600K @4,5GHz, 8GB DDR3, 128GB SSD, GTX970(GF7900GT), SB Audigy + YMF724F + DreamBlaster combo + LPC2ISA

Reply 106 of 128, by Stupid20CharLimit

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There's a someone by the name of rehsd that's making a 80286 homebrew pc. He plans to try to achieve dos 6.22 compatibility. One of the interesting things about this build is that he's not using any old vintage chipsets like past x86 homebrews have had. The chipset and bus control is done using modern components. It's way more work to make a homebrew x86 this way but performance boost from doing it this way would make it theoretically possible to run things like harris 25mhz 286's at their native speed. The thing preventing people from doing that type of thing on already existing 286 boards is that boards using chipsets capable of such speeds are extremely rare.

Reply 107 of 128, by Hamby

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This isn't an actual project, but it's a project I'd like to see (maybe I should start a separate thread talking about it?)

I was just thinking of my frustration getting networking under DOS working on VirtualBox, and started thinking of how I could make space to put the 486 I keep putting off building because I don't have the desk space for it... and I just wished that I had a 486 or Pentium 1 on a card I could just plug into my modern PC and use its keyboard/video/mouse output.

Then I remembered the Bridgeboard for the Amiga, which was a PC on a card that plugged into the Amgia.

I don't know how PCI-e works, but it should be more than fast enough to support a 486 or pentium 1 -based PC emulator card. Like an old-fashioned SBC, it could have video, audio and i/o options on-board, or just use the host PC's.
The socket plate could have plugs for USB-C and/or a custom port into which an external ISA/PCI/AGP daughtercard could be connected to provide slots for cards providing abilities not built-in to the Bridge card, such as a Voodoo 2.
I'd prefer it to use an actual 486 or pentium 1, but I'm sure it would need an FPGA for some of the other services, such as I/O and video support. Maybe not?

Reply 108 of 128, by RayeR

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I remember that some years ago I saw such PC card with 486 or Pentoum for old Apple computer that plugged in PCI slot. It allowed running native x86 apps. But I don't know how I/O was handled, if it was capable to render in a MacOS window. No idea if such card could also run in x86 PC under window, probably no due to lack of bridging drivers, reverse engineering would be needed.

Gigabyte GA-P67-DS3-B3, Core i7-2600K @4,5GHz, 8GB DDR3, 128GB SSD, GTX970(GF7900GT), SB Audigy + YMF724F + DreamBlaster combo + LPC2ISA

Reply 109 of 128, by wigyori

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RayeR wrote on 2023-02-20, 12:43:

I soldered the rest of DRAM chips (I had to borrow them from another working parity module because I don't have any other donor now) and it works fine in Alpha64. So when possible I will let manufacture them again with right thickness.
I'm not a fan of black or white opaque solder mask, I like visible traces. So I usually keep default green mask, only once I made red.

There will be additional interest from Sun users like me - for example the Sparcstation Classic uses 72-pin parity FPMs, and can handle 16Mbyte modules which are a bit hard to come by nowadays. Unsure if you want to opensource the PCB in the end or make it available to buy, but would love either.

Reply 110 of 128, by BitWrangler

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Two projects from Steven George, aka HardTechnology, for Sharp PC-4600 series computers (Small chance they may be applicable to PC-4500 or later models also) files at bottom of project pages. Licence ".. you can use them freely for personal, non commercial use." i.e. make your own, don't sell them...

8 Bit ISA expansion ...
https://blog.hardtechnology.net/2023/03/31/sh … 641-expbus.html

External 5.25/360kb Floppy Drive ...
https://blog.hardtechnology.net/2023/03/04/sh … 641-extfdd.html

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 111 of 128, by wiretap

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MigStorm ITX is working now.. basically I used the Minimig 1.1 and 1.3 design and adapted it for a full 68000 socket (with bus voltage transceivers 3.3/5v correction) for use with the Pistorm CPU accelerator, plus ATX power adoption. It fits nicely in a SFF ITX case to give you an OCS/ECS accelerated Amiga experience. Build, flash, and install a 68k CPU or Pistorm classic accelerator with Musashi or EMU68. Use Pistorm w/ Musashi + Amiga OS 3.x to take advantage of built-in WiFi. With use of the Pistorm, it is fully capable of playing Duke Nukem, Quake, etc on Amiga OS.

https://github.com/wiretap-retro/MigStorm-ITX

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My Github
Circuit Board Repair Manuals

Reply 112 of 128, by rasz_pl

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Now this is something mindblowing to me - EDO to FPM mod https://www.youtube.com/watch?v=nk8uEFpYbBw lift /OE and short to /CAS to make EDO ram chip generate FPM like timings. Works on old 386 chipset no problem.

Open Source AT&T Globalyst/NCR/FIC 486-GAC-2 proprietary Cache Module reproduction

Reply 113 of 128, by Tiido

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That is a clever idea, at first I thought it will have some timing related issues but now that I look at datasheets more, it actually should work without any problems with only exception being the additional loading on CAS line causing some timing margin reduction but that only matters for very fast configurations (i.e 50MHz FSB 486+ stuff)

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 114 of 128, by Thermalwrong

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rasz_pl wrote on 2023-05-05, 11:21:

Now this is something mindblowing to me - EDO to FPM mod https://www.youtube.com/watch?v=nk8uEFpYbBw lift /OE and short to /CAS to make EDO ram chip generate FPM like timings. Works on old 386 chipset no problem.

It does work on EDO simms as well, after seeing the video I modified 2x EDO sticks to be FPM and they work / pass memtest in a board that only takes FPM: Re: What retro activity did you get up to today?

Reply 115 of 128, by RayeR

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Uh, [headbanging on the table :], why we didn't know this a bit sooner. I have more EDO SIMMs and didn't need hunting for FPM ones, so I could make my SIMM PCB adapted for EDO chips. OK, let there be 3rd revision 😜 Maybe I could try to make it optional via 0R jumpers to configure for both FPM and EDO chips...

BTW here's DRAM FAQ with timings explained from video, 1996
https://www.bunniestudios.com/bunnie/dramfaq/DRAMFAQ.html

UPDATE: I already assembled one of my 72pin SIMM PCB with 4Mx4 EDO 60ns chips (non-parity yet) and it passed GoldMemory test in 486 MB at fastest timing 😀

Gigabyte GA-P67-DS3-B3, Core i7-2600K @4,5GHz, 8GB DDR3, 128GB SSD, GTX970(GF7900GT), SB Audigy + YMF724F + DreamBlaster combo + LPC2ISA

Reply 116 of 128, by StriderTR

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Forgive me if this has been suggested elsewhere, but I think the Z80-MBC2 (and the uTerm VT100 style terminal) is a fantastic little "homebrew" computer that's 100% free and open for anyone to download and build, or modify, themselves.

It's a Z80 based SBC with 128K of banked RAM, GPIO, and runs CP/M and more. When paired with the "uTerm" project (also open and free), you can build a fully functional CP/M machine straight out of the late 70's or early 80's.

z80-mbc2-board-3.jpg

MBC2: https://hackaday.io/project/159973-z80-mbc2-a … ew-z80-computer
Terminal: https://hackaday.io/project/165325-uterm

I built and modified one myself and it turned out great in my humble opinion. ( https://theclassicgeek.blogspot.com/2022/09/t … w-computer.html ) 😜

I recently had 5 more MBC2 PCBs made to try out some other build ideas.

supports.jpg
z80-frontpanel-leds.jpg
z80-inside.jpg
z80-obs.jpg

Last edited by StriderTR on 2023-12-02, 21:01. Edited 1 time in total.

Retro Blog: https://theclassicgeek.blogspot.com/
Archive: https://archive.org/details/@theclassicgeek/
3D Things: https://www.thingiverse.com/classicgeek/collections

Reply 119 of 128, by appiah4

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rasz_pl wrote on 2023-05-05, 11:21:

Now this is something mindblowing to me - EDO to FPM mod https://www.youtube.com/watch?v=nk8uEFpYbBw lift /OE and short to /CAS to make EDO ram chip generate FPM like timings. Works on old 386 chipset no problem.

Oh wow!

Retronautics: A digital gallery of my retro computers, hardware and projects.