Recent content by JonB

Interesting, Geoff. I wonder why it should take so much longer to log the drives than the BDOS does?

Your CMC is entirely different to a Superbrain, sorry.

Hi https://en.wikipedia.org/wiki/Paperback_Software_International I found a very early copy of VP-Planner in my collection. It's a BETA version dated 1989. Given its importance as a historical artefact (per the Wikipedia page), does anyone want it? Still works. Cheers JonB

All fair points. @Chuck(G) I'd think this is likely down to being after market addons, as the price of HDDs came down. I implemented uIDE for the Amstrad PCW first, and, due to the way it boots, it's floppy only boot. I couldn't figure out how to get it booting from the IDE device, although...

uIDE was designed and implemented by me, with help from Grant Searle's CP/M SBC source. I reverse engineered the BIOS and extended the boot ROM (which includes the FDD CPU code; original disassembly by Warren Gay in 1991). I've always suspected some sort of hardware glitch as the issue doesn't...

So.. hello all, I return with another odd question. There's a weird thing going on with my Superbrain when booting from uIDE. Drive A: occasionally spins up (I have implemented the motor control mod) and doesn't stop until a disk is inserted and the door closed. I put it down to a glitch of...

Regarding the drive stepper motor. Mine occasionally gets jammed with the heads closest to the spindle. When this happens, it just needs to be turned (the stepper motor, with the power off) a little so as to free up the head - that is, moving it away from the spindle. It only seems to happen...

I also produced a Lifeboat CP/M that booted from floppy and ran off a DOM. Have a search on the forum for details. The software is called XDRIVER and it is still downloadable. I did ask Ian to host it on his Model II downloads page but nothing came of the request. The hardware comprises a board...

https://www.cpcwiki.eu/index.php/UIDE_Universal_IDE_adapter_cards_for_Z-80_computers ..like a GIDE but much simpler (no GALs) with a Z80 shim.

You have PM... ;)

Yeah, they are old tantalum caps that look like diodes, next to the DRAM. Not electrolytic. But check the 12v & 5v rails for a short first.. you never know… My SB II has the dreaded beeeeeeeeeeeeeeeeeeep of death, gah! But I think SB I is ok. They’re in storage right now after a house move...

The Maslin archive has several images one of which is certainly for a Superbrain II (though it boots up in reverse screen mode). If your machine really is a SB II it might work. If so, it may even read / write a single sided disk, but only so far. The DPB will be configured for a QD drive, so...

I bet his A: drive is playing up and he is having problems booting...

That's a heck of a thing. Look for ROMs and dump them with a reader. There may be a monitor or other bootstrap. Gosh imagine getting CP/M running on it, assuming it's not a clone of something (like a Cromemco, as suggested). What a challenge!

Thanks Larry. I've replaced the HOT with a BU407 (same as the originbal part) and fitted a 2W metal film resistor at R478. I have the picture back and it is stable, but as before R478 is heating up and it is pulling over 1.4A. I've not attempted to soak test it as I know the resistor will go...