FreddyV wrote on 2025-12-17, 18:23:

Hi, […]
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Hi,

Still working on the PicoMEM 2, probably not available before March next year (Will send this board to prod next week and hope it work)

The attachment PicoMEM2.png is no longer available

I confirmed the DMA is working and even got GUS mixing working (No DMA support Yet) plus Sound Blaster (With DMA) working.

Here is an audio output of the PicoMEM 1.5 GUS:

The attachment Solstice_PicoMEM_GUS_Mono.mp3 is no longer available

I imagine this is with the RP2350

carlostex wrote on 2026-01-05, 14:00:

FreddyV wrote on 2025-12-17, 18:23:

Hi, […]
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Hi,

Still working on the PicoMEM 2, probably not available before March next year (Will send this board to prod next week and hope it work)

The attachment PicoMEM2.png is no longer available

I confirmed the DMA is working and even got GUS mixing working (No DMA support Yet) plus Sound Blaster (With DMA) working.

Here is an audio output of the PicoMEM 1.5 GUS:

The attachment Solstice_PicoMEM_GUS_Mono.mp3 is no longer available

I imagine this is with the RP2350

From the pincount this looks a RP2350 B. The RP2350A and RP2040 have a smaller case with only 15 pins per side.

I am very interested in these features for DOS:

- Memory emulation with 16Kb Address granularity:
> 128Kb of RAM can be emulated from the Pi Pico internal RAM with No Wait State. (4MHz ISA)
> We can emulate the whole 1Mb of RAM address space from the PSRAM. (With 6 Wait Stated for 4MHz ISA)
> EMS Emulation of Up to 6 / 7 MHz. (Only 4Mb for the moment as using the LoTech EMS Driver)
> Memory emulation is also used to add (4Kb of "Private" memory for the PicoMEM BIOS Usage)
> 16Kb of RAM is also added for disk access (Or other) even if 512Kb only is used for the moment.

I have an issue with trying to use UMBs on motherboards and either not being able to find enough or having them conflict with motherboard resources, leading to instability. Would something like this create a UMB "mask" over the motherboard's main UMBs (memory over 640K) that is guaranteed to be safe for programs to load into completely?

For example, I have an industrial socket 775 motherboard which has unusable UMBs in DOS, unless I disable USB 2.0 in the BIOS. And even then, I feel like I'm fighting for memory above 640K. I would love for there to be a way to reclaim UMBs for my drivers without sacrificing motherboard features that I want available in other operating systems.

lausvi wrote on 2024-08-23, 17:17:

I now have another question! I have a Commodore PC-I (https://www.zimmers.net/cbmpics/cpci.html), which I think would really ben […]
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I now have another question! I have a Commodore PC-I (https://www.zimmers.net/cbmpics/cpci.html), which I think would really benefit having a PicoMEM: it only has one ISA-slot (and only by using an external adapter: https://autumnhippo.com/products/pc1-xt) and it's very low-end XT clone. Having a hard disk, AdLib and networking on it would be a really neat treat (also no need for the bracket, hah).

I installed the PicoMEM on my PC-I and it does work (hard disk, AdLib and networking tested so far) BUT there is a somewhat random issue where sometimes (most of the time actually) the machine freezes at "PicoMEM Boot: Press A to boot from floppy , B for BASIC/ROM 1". The count-down at the end of the line stops at 1 or 2. At this point the internal floppy-drives's light is on, and when the boot halts, the light stays on (when it boots succesfully, the floppy drive light goes off after the hard disk boot has started). If I keep resetting the computer, I eventually get it to boot succesfully either by just not touching the keyboard at all, or bashing keys on the prompt and it just proceeds normally. I had no issues with the PicoMEM itself as I tested it on a loose 386 motherboard.

I noted some mentions of a timing issue with Commodore PC-10, could this be something similar (what was the issue on that machine?). Or as mentioned in a recent issue on the GitHub (https://github.com/FreddyVRetro/ISA-PicoMEM/issues/41) perhaps a power issue? Are there any easily reachable spots on the PicoMEM PCB to add additional capacitor for testing?

I did see couple of times an error about config not being saved/SD card not accessible, could this be a power issue as well? (The SD card is new and freshly formatted, although a cheap 4GB one).

Regarding my own issue way back in 8/2024: I've now tested the same setup again with the currently latest firmware and I haven't had a single issue booting the computer. So something released after late 2024 seems to have fixed, or at least greatly reduced, the halting-countdown issue I had with my PC-1.

Having a PicoMem adding an XTIDE bootable hard drive, an AdLib audio and NE2000 networking is a great addition for the otherwise very limited PC1 👍

Does anyone know if picomem's config software peacefully coexists with picogus? Picogeese? Basically, if I run the picomem setup software, can it tell the picomem from my picogus? Will the picogus config program screw up the picomem? I'd like to use the picomem as an NE2000 wifi board, and picogus for GUS emulation in the same XT class machine, and I'd really rather not have to pull one of the boards when I want to configure the other.

ubergeek72 wrote on 2026-04-05, 20:13:

Does anyone know if picomem's config software peacefully coexists with picogus? Picogeese?

To followup on my own post, they coexist just fine with picogeese. Even got it to work with my XT-IDE, which it beats in checkit's diskio by about 100k/sec. (10mhz micro8088 Z80). Still wrestling with wifi. At -36 to -80db, the connection establishes, but I've yet to get a successful DHCP. My toy computer workshop is out at the bitter end of my wifi. Antenna ordered. We'll see how that goes.

Followup to my followup. Got the wifi working. I have to cold boot the system every time, so I have some system bios stuff to tinker with, but packets are being exchanged.

ubergeek72 wrote on 2026-04-14, 08:28:

ubergeek72 wrote on 2026-04-05, 20:13:

Does anyone know if picomem's config software peacefully coexists with picogus? Picogeese?

To followup on my own post, they coexist just fine with picogeese. Even got it to work with my XT-IDE, which it beats in checkit's diskio by about 100k/sec. (10mhz micro8088 Z80). Still wrestling with wifi. At -36 to -80db, the connection establishes, but I've yet to get a successful DHCP. My toy computer workshop is out at the bitter end of my wifi. Antenna ordered. We'll see how that goes.

Z80. Sheesh. No. NEC V20.

Just got the Picomem 2 in and tried it out for the first time!

Some notes:

• I needed to flash the Picomem 2 with the 2026/06/21 firmware as it was showing "Optional ROM Bad Checksum = 00h" on boot. Flashing fixed this issue.
• Everything set up easily the same as the original Picomem. I did not yet download the new picomem utilities, the old ones worked for what I have tested so far (GUS aside).
• Needs a CR1220 batt for RTC. It has this printed right on the board, so if I'd looked closer I could have ordered one ahead of time.
• The PICOMEM.CFG I had on my microsd card from the Picomem 1 was not cross compatible. It can load into the settings menu with it but then will freeze on boot. It's a whole new Picomem with new capabilities so this isn't too surprising.
• There is no bracket sent with the card (ordered from Flamelily). The Greetings on the back of the card do mention help with a 3d printed bracket, so maybe this is coming in the future?
• The ports on the card are aligned with the very bottom of the slot. Unfortunately since most of these old computer's tolerances are not very good this prevents it from fitting. This is the same as the Picomem 1 though and I had already dremmeled out of a bit of a slot to get it to barely fit in my 286. It will just barely wedge into my 5150 without cutting, although that leaves the USBC port inaccessible while it is installed (which is pretty minor, easy enough to pull it for a firmware upgrade).
• The OLED display works out of the box and is really cool. I also connected a 5 way momentary switch, but since I could not find a combo OLED/switch board and didn't yet make a custom cable I stole a second ground from the nearby LED pins. It works, and hopefully isn't bad to do?
• The GUS was not recognized by the one piece of software I current have to test it (Legend demo). However basic research says I will need to init the card, at least if it acts like an original GUS. I'll play with this more later tonight, I see a new PMINIT with GUS switches.

I'll be playing with the new capabilities (SB/GUS on the 286, more no wait state ram and RTC on the 5150) later.

Thanks FreddyV for your continued amazing work!

Quick follow up since I forgot to post the other day. Getting sound blaster and gravis ultrasound working was as simple as setting BLASTER and ULTRASND and then running pminit. My CR1220's came in and the clock also functions perfectly and holds time. The astclock.com on the git repo is one that can't display anything past the year 99, but it still actually sets the DOS date properly. The astclock with the year display fixed also functions with the picomem 2.

Setting floppy's and HDD's works great as in the original picomem, and as a surprise unlike last time I tried in a 5150 it plays well with the built in floppy drives. Setting a disk in picomem will "override" the drive. Setting the picomem2's disk to "None" allows the computer to access the physical drive again.

EMS mounts and reports as there through chkdsk, though I have not extensively played with it yet.

PicoMEM 2 available now : https://www.serdashop.com/PicoMEM2

Kahenraz wrote on 2026-01-31, 17:59:

I am very interested in these features for DOS: […]
Show full quote

I am very interested in these features for DOS:

- Memory emulation with 16Kb Address granularity:
> 128Kb of RAM can be emulated from the Pi Pico internal RAM with No Wait State. (4MHz ISA)
> We can emulate the whole 1Mb of RAM address space from the PSRAM. (With 6 Wait Stated for 4MHz ISA)
> EMS Emulation of Up to 6 / 7 MHz. (Only 4Mb for the moment as using the LoTech EMS Driver)
> Memory emulation is also used to add (4Kb of "Private" memory for the PicoMEM BIOS Usage)
> 16Kb of RAM is also added for disk access (Or other) even if 512Kb only is used for the moment.

I have an issue with trying to use UMBs on motherboards and either not being able to find enough or having them conflict with motherboard resources, leading to instability. Would something like this create a UMB "mask" over the motherboard's main UMBs (memory over 640K) that is guaranteed to be safe for programs to load into completely?

For example, I have an industrial socket 775 motherboard which has unusable UMBs in DOS, unless I disable USB 2.0 in the BIOS. And even then, I feel like I'm fighting for memory above 640K. I would love for there to be a way to reclaim UMBs for my drivers without sacrificing motherboard features that I want available in other operating systems.

I still have these questions about PicoMEM and it's a bit too expensive for me to buy just to try it out.

PicoMEM 2 panel looks this this :

dreamblaster wrote on 2026-07-01, 10:51:

PicoMEM 2 panel looks this this :

The attachment panel_picomem2.jpg is no longer available

Thanks for the picture, Serge!
Can you also post one of the 5.25" panel version?

PicoMEM 2 is amazing! 😀

So much improvements, especially in the audio section.
For me the best is the added GUS+GM Support.
Very well done @FreddyV and all involved people.

I wonder if it is possible to integrate MUNT for MT32 compatibility like the MT32-Pi.
This would make it the absolutely all-in-one soundcard of my dream.

crusher wrote on 2026-07-02, 06:18:

I wonder if it is possible to integrate MUNT for MT32 compatibility like the MT32-Pi.
This would make it the absolutely all-in-one soundcard of my dream.

Would probably require another dedicated rp chip, for which I have been advocating for like forever 😀 $0.8 BOM bump in exchange for doubling horsepower.

rasz_pl wrote on 2026-07-02, 06:23:

crusher wrote on 2026-07-02, 06:18:

I wonder if it is possible to integrate MUNT for MT32 compatibility like the MT32-Pi.
This would make it the absolutely all-in-one soundcard of my dream.

Would probably require another dedicated rp chip, for which I have been advocating for like forever 😀 $0.8 BOM bump in exchange for doubling horsepower.

Having a PicoMEM with dual RP2350 chips would also allow it to add even more zero-waitstate RAM to low-RAM host systems, right?

And indeed, who knows what other cool features could be realized with a board carrying two of those chips.

ed208 wrote on 2025-04-16, 13:56:

I'm looking at getting a PicoMem for my Amstrad PC1640. I'm having a nightmare getting XT-IDE to work on it.

Have the issues with sometimes not working on the Amstrad been ironed out recently? If it's stable now I'll go and buy one of your boards. Lovely work by the way!

Keep up the good work!

Hi nothing wrong with trying the PicoMEM on the Amstrad PC1640 (curious myself 😀 ), but I'm surprised to hear about the problems of getting XT-IDE to work on it. Can you give more detail please? I have tried over the years several iterations of the PC1640 and XT-IDE, and never had a problem. That said, I failed however miserably on getting EMS extensions (to use the upper memory blocks between 640k and 1M) to work on the PC1640 as on the IBM 5150.

O7

Hi,

Has anyone tested the PicoMEM 2 with Sergey Kiselev's Micro 8088 computer? I am doing some testing with this setup, and almost everything works like a charm: Wi-Fi, HDD emulation, floppy emulation, sound, and RTC, except for the USB mouse. The PicoMEM 2 BIOS reports that a USB mouse device has been detected. Of course, I have played around quite a lot with the PM2 BIOS settings (USB Host: On, USB Joy: Off, etc.). My setup has no extra hardware, just the Micro 8088 (BIOS 1.02), Sergey's VGA card, and the PicoMEM 2. See the attached photo.

I have tried Freddy's own disk HDD images (D33_ENG.img and D622_500M.img). Both Microsoft's MOUSE.COM driver and CTMOUSE fail to detect the mouse. Oddly, PMMOUSE seems to detect and load a PS/2 mouse correctly, but unfortunately, the mouse itself does not work. I have also tested the bootable Svarog86 FreeDOS floppy image, but CTMOUSE fails to detect anything there too.

I have also tested older versions of the Micro 8088 BIOS, with the same result. I have tested several different mice as well. If you think I am missing something here, please let me know. Thanks!

Problem: PicoMEM and PS/1. S doesn't show BIOS.

Solution: Put BIOS C800 and PREBOOT in config.txt