The Sinclair QL Forum

Looking at attaching a serial keyboard to the keypad matrix using a PIC it looks like a relatively trivial job to have the PIC completely replace the 8049. The SuperHermes seems to have done the job with lots of extras but I see it is out of date with the PIC 17C44 and it requires a special board with lots of connections that seems overkill to me just for a single chip replacement. I could port the PIC 17C44 to an 18F series chip relatively easily I think because Microchip tend to keep peripherals and even architectures of their low end CPUs compatible for easy upgrade paths. However for me a 28 pin PIC on a PCB that plugged in to the 8049 socket seems the best solution and it could have any extra connectors on the PCB with the 28 pin device like an extra or replacement serial port & the serial keyboard. I say trivial to change the 8049 to a PIC because having written things like 48K of assembler for PICs in the past and then doing it in C it is trivial. I shall code the PIC assuming it is to replace the 8049 for my serial to QL matrix keyboard conversion leaving the possibility to go the whole hog if there is any interest in an 8049 replacement.
On the PIC 17C44 to an 18F series chip if there is an interest in doing it and the assembler for the PIC 17C44 exists I could do an assessment of the viability for a conversion and if simple actually do it if it is needed.

All you really need are the details of the ZX8302 <> IPC communications and the format of the various 'commands' exchanged between these 2 chips - you then 'just' need to code your pic to do the right thing in response to the communications from the ZX8302, but I would not have said this is particularly trivial.

What's your objective?

To replace the 8049 for a PIC
To add additional functionality?
To fix any of the shortcomings in the original 8049 code?
Will it still need to provide serial receive function?
Will it still need to handle the keyboard?
Will it still need to drive the speaker?

I don't think the source for the SuperHermes PIC is available

No, currently there are no sources. Tony Firshman checked and reports that he does not have the sources and Lau didn't respond to my last enquiry anymore Maybe it would help if other people asked, too, or maybe not, no idea.

Or... Possible nice ready made USB keyboard and mouse solution using cheap CH559 (8051 core):

Video: https://ru-clip.com/video/Th88RiSmj2w/u ... -chip.html
English docs: https://github.com/kprasadvnsi/CH559_Doc_English
Code: https://github.com/atc1441/CH559sdccUSBHost

The device can be updated over USB, downside is flash 200 max.

Pr0f wrote:All you really need are the details of the ZX8302 <> IPC communications and the format of the various 'commands' exchanged between these 2 chips - you then 'just' need to code your pic to do the right thing in response to the communications from the ZX8302, but I would not have said this is particularly trivial.

Pr0f wrote:Another alternative is replace both chips with one plugged in the socket that would require the least wires from the other socket. It seems stupid for the cpu to talk to one chip then that one talks to another given the technology available today.

Pr0f wrote:What's your objective?

I don't have one other than a serial to QL keyboard matrix as I said above.

Pr0f wrote:To replace the 8049 for a PIC
To add additional functionality?
To fix any of the shortcomings in the original 8049 code?
Will it still need to provide serial receive function?
Will it still need to handle the keyboard?
Will it still need to drive the speaker?

All with a new chip would make sense.

Pr0f wrote:I don't think the source for the SuperHermes PIC is available

Has it been disassembled or is it still in a ROM?

Silvester wrote:Or... Possible nice ready made USB keyboard and mouse solution using cheap CH559 (8051 core):

Qlub does that doesn't it?

Ruptor wrote:

Silvester wrote:Or... Possible nice ready made USB keyboard and mouse solution using cheap CH559 (8051 core):

Qlub does that doesn't it?

Dunno, what's QLub ?

IIRC the CH559 code used outputs SPI, though code can be changed. Device may be powerful enough in itself to replace IPC (serial ports, IO to scan QL keys). Electrodragon.com do some cheap developement boards (https://www.electrodragon.com/product/c ... 5x-series/). I was going to get some but with VAT changes this year not sure of situation - don't want to get stung for collection fees (Ebay et al pay VAT). Like to try it out with MT8808.

IIRC Tony F tried to make some more SuperHermes a while ago without success, so it doesn't bode very well for ressurecting a PIC version.

Silvester wrote:Dunno, what's QLub ?

Here uses cheap board
viewtopic.php?f=2&t=3590&hilit=QLUB

Ah, no, that's a completely different thing, I recall it now, QLub is USB Device to QL network interface. Wheras the CH559 with the github code provides an easy USB Host interface for keyboard and mouse (and with other code, as host to other USB devices).

Ruptor wrote:Has it been disassembled or is it still in a ROM?

which bit Ruptor ?

Hermes is in the flash of the PIC - and I don't think it can be accessed easily - but I haven't tried

The other information relating to original IPC or Hermes, and the contents of the ROM (Minerva sources) are well documented enough to re implement the protocol on another device.