Recent content by prime

Hi all, I recently bought a pre-made Micro8088, with a CF insterface and 8 bit backplane board. To this I have added a 16 bit Trident VGA card (jumpered for 8 bit operation) and a IDE multi IO card (IDE/2S/1P/Floppy) card. I have jumpered this to disable the IDE interface as that will only...

I'd say network card of some sort, WD1935 seems to be a "Synchronous Data Link Controller", maybe Token ring, or something like that. Cheers. Phill.

A Friend of mine is re-crating and cleaning up the original Issue 5 board, details here : https://www.stardot.org.uk/forums/viewtopic.php?t=30101 Cheers. Phill.

Got one of these hopefully on the way to me later in September...... Now what I'd be interested in seeing is the source code for the CPLDs.... with that all sorts of things would be possible. One thing I wondered about was replacing the Upper 128K RAM with a 512K, you'd of course need to also...

Hi all, I've been designing a 16 bit XMS board for use on AT class motherboards that have limited onboard expansion. For example I have a Commodore PC-40-III that can only have 1MB onboard. The board currently consists of between 2 and 8 AS6C4008-55PCN 512K x 8 bit SRAMs (one each for the high...

Hi all, Anyone know of a convenient way of adding a reset button to the 8MHz version of the 5170 motherboard? Cheers. Phill.

Hi all, Does anyone have the schematic for the Holmes Sprinter III, the documentation refers to a schematic but it's not included in the PDF file. Cheers. Phill.

Hi all, I have an IBM branded TM-100-2A 40 track DS drive that I'd like to repair. Last time it was used it suffered a mildly catostrophic failure (c36 a 475, which if I'm reading correctly is 4.75µf, tant capacitor went pop and caught fire!). I can source and replace this cap easily enough but...

Hi all, I have a model 3 with a FreHD, which can boot LDOS 5.3.1 or Newdos. I can format a floppy disk from both but is there an easy way of transfering the system to them so that they are bootable on a mchine without a FreHD (or with the HD disconnected). Cheers. Phill.

Hi all, Does anyone know if there is an archive of the source / a dissasembily of either TRSDOS or LSDOS for the TRS80 Model 3 available anywhere? I've searched and come up with nothing. Cheers. Phill.

Hi all, I have a working TRS80 model 3 motherboard, but that's all I have :( I'm using a PS2->Crosspoint switch to implement the keyboard, and have a circuit using a 74LS02 and some discretes to combine the syncs and video into a composite sync like signal. However when I feed this into one...

Hi all, I keep seeiing refferences to the later versions of the Model 4 using a 177x based floppy controller (e.g. Wikipedia), but cannot find a schematic for this. Does anyone know if it is available and if so where? Cheers. Phill.

Hi all, I have one of the Universal PET boards with the 6845 video controller, that I'd like to power up. I have tested the board in my PET 3008 and it seems to work without problems. However I only have one PET case :( So does anyone have the specs of the mains transformer please, or advice...

Hi all, Following on from my post about imaging.... Is there documented anywhere an explanation of the translation scheme used by the XTIDE universal bios ? Also is there a way of enquiring of the drive e.g. via an INT call to find out what scheme is currently in use? Cheers. Phill.

Hi all, So here's the setup I have a 5150 PC with a WD MFM controller in it, attached to this is a 20MB hard disk. This all works fine but I wanted to take a dump of the hard disk for backup / emulation purposes. The machine is running PC-DOS 4. So I installed an XT CF lite rev 2, jumpered so...