ROM service call 49/&31

[tom_seddon]

BeebWiki's ROM service calls page mentions ROM service call &31:

&31 Keyboard driver call.

Anybody got any info about this? I can't find any evidence that any of the Master MOS versions I've got issue this service call, nor do the Compact ARABIAN-C or International ROMs try to handle it. (The International ROM does handle service call &30 - translate Internationalised keyboard keypress.)

--Tom

P.S. while doing a quick first draft disassembly, just to check which service calls were being handled, I did notice that the ARABIAN-C ROM calls directly into MOS 5.11i! It does a jsr $e94e in several places, bypassing WRCHV to go to OSWRCH directly. A bit rude when there's a perfectly serviceable NVWRCH entry point at $ffcb already...

[james]

&31 Keyboard driver call.

Here's some, unseccessful, digging.

Tbere are only reason codes up to &2C in:

• New Advanced User Guide 1987
• Dabhand Master Operating System (2nd Edition) 1988
• Sprow's SWR Guide https://www.sprow.co.uk/bbc/library/sidewrom.pdf

Not mentioned at all in:

• The MASTER 128 SYSTEM ROM USER GUIDE (ie MOS 3.50)
• Master Series Compact Application Note of Sep '86

However, there is an mention of a "Sideways ROM keyboard driver" in OSBYTE &AC https://beebwiki.mdfs.net/OSBYTE_%26AC, it appears to be distinct from the "International keyboard driver" which uses Service Call &30. OSBYTE &AD also mentions it and links to the page for MOS 5.11i https://mdfs.net/System/ROMs/AcornMOS/Compact511/

Looking at that, if it's it not in International ROM, is service call &31 in UTILS 1.10c (different from 1.10 of MOS 5.10)?

Otherwise, maybe the person who likely authored the page knows:

https://beebwiki.mdfs.net/Service_calls

Edit: nor was the mention in any Acorn Application Notes

[jgharston]

I've been digging and can't remember where I saw &31 as a keyboard call. There's a possibility I may have seen it in a list as "&30 and &31: keyboard", and documented &30 as in the Compact when I disassembled the Compact code. Which still leaves tracking down where I saw it as "&30 & &31".

[james]

Anybody got any info about this?

You might try asking gtoal, as the source to the Arabic ROM appears to be on his website, so it may have been an area he was working in https://gtoal.com/acorn/files/