RayeR wrote on 2022-10-08, 23:28:

And is there some project replicating 36-bit parity 72p SIMM? I would need some higher capacity for my Alpha and they are much more rare than common 32-bit SIMMs...

IBM seemed to be the most common parity 72 pin, but they had their own Presence Detect coding, so it might be necessary to swap resistor position on the PCB. 8MB are really common but I don't know about 32MB and it's probably a bit of a risk unless you can find a big scrap lot to work over.

@oxcats if you're browsing I don't have PMs yet 🤣. Any info you can share would be great 😀

wiretap wrote on 2022-08-08, 12:58:

The one hooked up to the Amiga in the video is a 40% Romeo keyboard with GMK Laser keycaps and a 3D printed case from Thingivers […]
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The one hooked up to the Amiga in the video is a 40% Romeo keyboard with GMK Laser keycaps and a 3D printed case from Thingiverse.
Keyboard: https://www.cftkb.com/shop/romeo
Case: https://www.thingiverse.com/thing:4540218/files
Keycaps: https://drop.com/buy/drop-mito-gmk-laser-cust … ctionIds=968364
Switches: Gateron Green 5-pin https://www.aliexpress.com/item/2255800821908641.html

Hello Wiretap!

I do have to ask how/where did you get ahold of that "C=" commodore keycap ?
I checked the keycaps link above but beside the horrendous price, couldn't find any.

Offtopic to that 😀 , it's ironical how those Chinese sellers make all kind of keycap labeling, with all possible crap from snakes to poop emojis but so far I could not find one making a "C=" or some "A" keycaps.

Thx,
Thomas

C= 1u keycap: https://www.wasdkeyboards.com/commodore-cherr … -mx-keycap.html
Amiga 1.25u keycap: https://www.wasdkeyboards.com/os-cherry-mx-keycap-set.html

72-pin SIMM template: https://github.com/wiretap-retro/72-pin-SIMM-KiCAD-Template

OK, it could help a little bit to making a 36-bit parity SIMM. I have some JEDEC PDF with pinout and sch. of 36-bit SIMM.

wiretap wrote on 2022-10-18, 16:32:

72-pin SIMM template: https://github.com/wiretap-retro/72-pin-SIMM-KiCAD-Template

pic.png

YEEESSSSS THANK YOU

Got a proof of concept 50ns EDO sim working tonight.

Is your module wired to work also in 36-bit parity mode? Did you made there some size selection solder jumpers?
Do you have a cheap source of high density 4-bit/16-bit DRAM FPM/EDO chips? I din't have any spare and I 'm a bit reluctant to solder them from old working SIMM modules.

RayeR wrote on 2022-11-03, 11:54:

Is your module wired to work also in 36-bit parity mode? Did you made there some size selection solder jumpers?
Do you have a cheap source of high density 4-bit/16-bit DRAM FPM/EDO chips? I din't have any spare and I 'm a bit reluctant to solder them from old working SIMM modules.

This is not a parity compatible chip, the source is also not that cheap so I'd be sourcing more from somewhere else. I didn't have to change the size selector as it was the same size chips on the module. I'll probably souce more 50ns parts from high density simms on ebay or something.

The parity support doesn't depend on specific chip, normal DRAMs are used. As I see on your photo, your SIMM has two 16-bits DRAMs and one unpopulated 4-bit DRAM footprint so it would be enough to solder the 4-bit DRAM and you get 36-bit parity SIMM module. But maybe also ID pins should be changed. I don't know what schematics did you use. My goal would be to make universal SIMM that can be assembled as both 32/36-bits with different capacity chips selectable by solder jumpers to accomodate various DRAM chips that you can get...

RayeR wrote on 2022-11-04, 01:20:

The parity support doesn't depend on specific chip, normal DRAMs are used. As I see on your photo, your SIMM has two 16-bits DRAMs and one unpopulated 4-bit DRAM footprint so it would be enough to solder the 4-bit DRAM and you get 36-bit parity SIMM module. But maybe also ID pins should be changed. I don't know what schematics did you use. My goal would be to make universal SIMM that can be assembled as both 32/36-bits with different capacity chips selectable by solder jumpers to accomodate various DRAM chips that you can get...

Gotcha, yea that's a neat idea, I'd also use a side mount actual jumper as well so it' easy to change. Someone up thread kindly posted a template and I'm going through learning kicad to get the PCB's printed.

ALEKS wrote on 2021-03-16, 07:28:

I wasn't aware that my projects present such interest. I updated the web pages and included the Gerber files for the designs tha […]
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I wasn't aware that my projects present such interest.
I updated the web pages and included the Gerber files for the designs that I tested and deemed as working.

PS: You might want to modify the links as I moved some pages. Also I think the audio interface card is missing from the list above.

Thanks,

Hi Alex,

Your 386DX project is awesome. Any chance you have some PCB leftovers for sale such as the ISA backplane and the 386 SBC ?

LMK and thanks for sharing those projects with the community.

Thx !

Marc

Holy shit I dont know how this one got under the radar despite author posting here all the way back in 2016! Re: 8088 MPH: We Break All Your Emulators

Ted Fried of MicroCoreLabs:

MCL86 - "open source, cycle accurate, microsequencer-based FPGA core which can be used as as an embedded processor or as a drop-in replacement for the Intel 8088 or 8086". Runs on Xilinc, Lattice and Altera.
https://microcorelabs.wordpress.com/2016/03/0 … the-mcl86-core/
https://github.com/MicroCoreLabs/Projects/tree/master/MCL86
https://hackaday.io/project/188412-mcl86-cycl … -8088-fpga-core

MCL86+ - "CPU replacement board which uses a Teensy 4.1 microcontroller board to emulate the Intel 8088 microprocessor which is used in the original IBM Personal Computer models 5150 and 5160". In turbo mode "The results is a substantial performance increase! Some tools report that the IBM XT runs at speeds close to an 80386."
https://microcorelabs.wordpress.com/2022/01/2 … tor-for-ibm-pc/
https://microcorelabs.wordpress.com/2022/07/3 … lerator-update/
Source code, schematics, and PCB files for the MCL86+ are now on GitHub.
https://github.com/MicroCoreLabs/Projects/tre … master/MCL86%2B

When I'm designing 36-bit parity FPM SIMM I run into trouble with parity DRAM chips. They are used e.g. 4M x 4bit but it is a special chip that has 4 CAS pins while common DRAM has only one. So I decided to rather use 4 single-bit chips e.g. 4M x 1b but there's another problem that all of them I have found, e.g. HYB514100BJ, has separate Data in and Data out pins instead one bidirectional output + enable. So I'm thinking to use four common chips 4M x 4bit where 3 bits of 4 will be wasted. But it would remain possible to harvest common DRAM chips from non-parity modules, e.g. making 2 new parity modules from old 3 non-parity ones. Someone has better idea or know a cheap source of 4-CAS chips?
OK, I checked some SIMM module with multimeter and they simply conneted Din and Dout together. But as I look for my spare chips I don't have high density 1-bit chips anyway so I will use 4 x 4-bit chips as they are more common.

I know it's silly, but I'd like to see an open source project for a 3D video card.
Obviously it wouldn't be able to compete with Nvidia or AMD.
But... if it was PCI-e and Voodoo3 2000 3D compatible (essentially a Voodoo 3D clone with PCI-e connection)... that I'd want to see, even if it's not as good as an older Nvidia or ATI 3D card.

I'd also be happy to see a Voodoo 3 in FPGA on a 16-bit ISA card.

(Hmm... I have a modern motherboard with a PCI slot... I wonder if I could run a modern linux with a classic PCI Voodoo card?

I have seen some russian Voodoo "magic" where they e.g. added a HDMI output, I think it was still PCI but shouldn't be technically problem to add some PCI-E to PCI bridge... AFAIK there's no official website with some details and documentation but only some forum thread, maybe someone else knows more...

to the simmsperts: any chance of sram simms?

Hamby wrote on 2023-01-02, 16:08:

I know it's silly, but I'd like to see an open source project for a 3D video card. Obviously it wouldn't be able to compete with […]
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I know it's silly, but I'd like to see an open source project for a 3D video card.
Obviously it wouldn't be able to compete with Nvidia or AMD.
But... if it was PCI-e and Voodoo3 2000 3D compatible (essentially a Voodoo 3D clone with PCI-e connection)... that I'd want to see, even if it's not as good as an older Nvidia or ATI 3D card.

I'd also be happy to see a Voodoo 3 in FPGA on a 16-bit ISA card.

(Hmm... I have a modern motherboard with a PCI slot... I wonder if I could run a modern linux with a classic PCI Voodoo card?

I have been throwing around the idea of a voodoo 5500 pci project. But I will need help. also.. time to work on it will be sparse.
if there are a lot of people who want to actively help me study the data sheets, help with design rules and practices, advise about layout etc. I'm more than willing to help.

there is already a really nice project for this from Anthony in Russia though which honestly would be pretty hard to beat. I mean he has the heatsinks and back bracket even figured out as well as 128mb. so one kinda wonders if there is even much point in doing the project when one could just buy from him. anyway, if someone wants to organize a thread/group effort. count me in as the pcb drafter.

Open source 2.5 IDE SSD, linking Hackaday writeup for description https://hackaday.com/2023/01/19/that-old-thin … ce-2-5-ide-ssd/
It's pretty trivial to adapt to 3.5

( a bit OT for this, so open thread to discuss, but hardware meddlers with more modern stuff might like this recent post too https://hackaday.com/2023/01/19/what-else-is- … -slot-good-for/ )

Hm, "So how does it work? The SM2236 is actually a CompactFlash (CF) controller" So why to bother with soldering BGA flash chips when you can get a cheap CF-IDE adapter and put CF there...