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by jgharston
Mon Dec 11, 2017 8:39 am
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

I'm thinking now that the bug is that the args parsing is leaving an <00> terminated string and the subsequent fopen (OSFIND) is expecting an <0d> terminated string. ... I wonder if PiTubeDirect's implementation of the OS_Find API should interpret any control character as the filename terminator? T...
by jgharston
Mon Dec 11, 2017 8:31 am
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

Going back to the thread topic of the Jupitor emulator, the code starts up with: swi OS_GetEnv // Get application space limit // R0=>command line // R1= environment limit // R2=>startup time bic r13, r1, #7 // Stack base at environment limit (rounded down to nearest 8) bl __appentry // call applicat...
by jgharston
Mon Dec 11, 2017 7:57 am
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

Grrr rant rend grind tear. I was doing a bit of testing before going to bed, and a great chink of the above is wrong. On the PiTube Native ARM CoPro *TESTARM was always failing because there's an inbuilt *TEST command and the command parser doesn't check for the end of the command name so matches an...
by jgharston
Sun Dec 10, 2017 11:17 pm
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

Here we are. The following code will read the command line parameters to local memory on RISC OS, the ARM Development System, the Sprow ARM CoPro and the PiTube Native ARM CoPro. ( link ) MOV R0,#1:MOV R1,#0:MOV R2,#0 SWI "XOS_Args" :\ R2=address of comand line parameters ORRS R2,R2,R2:BMI...
by jgharston
Sun Dec 10, 2017 8:11 pm
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

Can anyone point me at where using OSARGS to read the command line is documented? It's not obvious from here: http://beebwiki.mdfs.net/OSARGS OSARGS doesn't read the command line, it reads the address of the command line. A=1, Y=0, X=>address returns address of command line in address MOV R0,#1 MOV...
by jgharston
Sat Dec 09, 2017 11:12 pm
Forum: hardware
Topic: Jupiter Ace emulator
Replies: 42
Views: 563

Re: Jupiter Ace emulator

Yes. How do you parse the command line params? I'm using some code from Sprow's ARMTDMI C coding example. It copies the command line out of the I/O processor then parses the arguments. It works perfectly on my machine (model B, VideoNuLA and GoSDC using ADFS). You shoudn't need to do that, OS_GetEn...
by jgharston
Fri Dec 08, 2017 10:01 pm
Forum: emulators
Topic: MAME: Tube devices
Replies: 68
Views: 2995

Re: MAME: Tube devices

Just noticed something a little strange.... Your Client ROM trace doesn't seem to match the disassembly on JGH's site for v1.00: http://mdfs.net/Software/Tube/ARM/v100.zip There are several versions of various versions(!) of the ARM Client ROM. For instance, the A500 we were looking at at ABUG is a...
by jgharston
Thu Dec 07, 2017 1:25 pm
Forum: hardware
Topic: Unusual mask ROM in Master 128
Replies: 8
Views: 230

Re: Unusual mask ROM in Master 128

Ah, that's actually:

Code: Select all

Socket    ROM
A14 --|>--A14
A15 --|>--A15
A16 --|>--A16

So what that's saying is the that the eight banks of 16K in the ROM were the wrong way around.
by jgharston
Thu Dec 07, 2017 1:14 pm
Forum: off-topic
Topic: online study?
Replies: 18
Views: 439

Re: online study?

I was looking at Distance Learning Portal the other day thinking about making another try for next September. I have a similar concern to the OP in that if I'm not actually having to physically turn up at a physical location I'll end up drifting off.
by jgharston
Thu Dec 07, 2017 3:45 am
Forum: off-topic
Topic: online study?
Replies: 18
Views: 439

Re: online study?

Today I've just got a job rejection today for an IT Engineer position, turned down because I'm too experienced. What they basically meant was "You'll show us all up for the clueless people we really are", bet whoever interviewed you had no idea. Interview? What's one of those? Actually ge...
by jgharston
Thu Dec 07, 2017 3:43 am
Forum: hardware
Topic: Unusual mask ROM in Master 128
Replies: 8
Views: 230

Re: Unusual mask ROM in Master 128

But... by my understanding ~CS is tied permanently low on the MOS ROM in the BBC Master, i.e. it's always enabled. If early chips got that wrong, why the need for the logic chip? Would it not have sufficed for the carrier to tie CS to +5V? Hmmm, you're right. Any chance Andy could trace the connect...
by jgharston
Wed Dec 06, 2017 11:50 pm
Forum: software: other
Topic: Disk images and Gotek floppy emulator
Replies: 0
Views: 77

Disk images and Gotek floppy emulator

At the recent ABUG Leicester there was some experiments with a "cheap Gotek floppy emulator clone": see photo We found it turned its nose up at short disk images that were not the exact size that imaging all 40/80/160 tracks of a physical disk would create including all unused sectors. I'v...
by jgharston
Wed Dec 06, 2017 11:27 pm
Forum: hardware
Topic: Unusual mask ROM in Master 128
Replies: 8
Views: 230

Re: Unusual mask ROM in Master 128

It says "MOS 3.20 with incorrect CS". I'm curious what the 'incorrect CS' might refer to. EDIT: Thinking about it, I'm wondering if CS is chip select. Yes, it's Chip Select. It incorrectly had a CS line (active high) instead of a ~CS line (active low), so came on a mini-PCB with an invert...
by jgharston
Wed Dec 06, 2017 1:54 am
Forum: hardware
Topic: Clwyd Technics Colour Palette enhancer
Replies: 7
Views: 278

Re: Clwyd Technics Colour Palette enhancer

Yes, I'd have loved to have something like this back in the 80s, or even just have known that this sort of stuff existed. I must have been reading the wrong magazines. Looking in archives I can only find one reference to the Clwyd board and that was way back in 1982. Years after making my MIDI inter...
by jgharston
Wed Dec 06, 2017 1:42 am
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1003
Views: 74993

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

The data is put "temporarily" in registers in the NMI handler. The only source of any timing mismatches would be because the NMI handler is running in main RAM at &0D00 and the 4MHz board lets anything in main RAM run at 4MHz, so the devices at the other side of the Tube may not be abl...
by jgharston
Wed Dec 06, 2017 1:28 am
Forum: off-topic
Topic: online study?
Replies: 18
Views: 439

Re: online study?

Pointless, I've got many Accounting letters after my name, sat on dole for a total of 3.5yrs :lol: could be a doctor of science, & stack shelfs at crappy Tesco. . . its all about experience , and brown nosing thick managers nowadays :roll: but, if keeps your mind of things & get 'study' mon...
by jgharston
Tue Dec 05, 2017 3:52 pm
Forum: off-topic
Topic: online study?
Replies: 18
Views: 439

Re: online study?

Last year I applied to do a Masters, with half the course material being stuff I'd already done before, but was turned down for having been to university too long ago (1987), and having no relevent experience (err... isn't the whole point of going to uni is to get the experience?).
by jgharston
Tue Dec 05, 2017 1:37 am
Forum: emulators
Topic: Printing a program listing
Replies: 14
Views: 354

Re: Printing a program listing

jgharston wrote:I'll give it a try on the PDP11....
Wey hey! Works perfectly! :D

Though, after five years I got unemployment to zero, had a current account surplus and inflation down to 4%, but got kicked out in an SDP landslide!
by jgharston
Tue Dec 05, 2017 1:20 am
Forum: emulators
Topic: Printing a program listing
Replies: 14
Views: 354

Re: Printing a program listing

danielj wrote:Here you go, I've attached it to this post.

Seems to work perfectly well on BBC BASIC for Windows, other than it annoyingly complains about lower case keypresses, so it most likely will run on ARM BASIC and any other BBC BASICs as well. I'll give it a try on the PDP11....
by jgharston
Sun Dec 03, 2017 9:07 pm
Forum: general
Topic: New BeebWiki articles
Replies: 34
Views: 4786

Re: New BeebWiki articles

The following articles in the BeebWiki were recently updated: * Keyboard * Writing to EEPROMs * Video ULA * VDU 23 * VDU 19 * USR * Testing for sideways RAM * Sophie Wilson * SCSI commands * Screen editing * Richard Russell * Program format * Physical colour numbers * Multiplatform programming * INP...
by jgharston
Sun Dec 03, 2017 5:47 pm
Forum: programming
Topic: ASM Newbie: Delays, waiting X seconds
Replies: 1
Views: 131

Re: ASM Newbie: Delays, waiting X seconds

If you don't mind a keypress terminating the delay early: LDX #centiseconddelay AND 255 LDY #centiseconddelay DIV 256 LDA #129:JSR OSBYTE If it must delay the entire time, the simplest is to use *FX19 to count 1/50s VSyncs: LDX #fiftithseconddelay AND 255 LDY #fiftithseconddelay DIV 256 .waitloop TY...
by jgharston
Thu Nov 30, 2017 11:28 am
Forum: software: other
Topic: GXR questions
Replies: 5
Views: 306

Re: GXR questions

Some example of actual software that used the GXR would be in order. If there's not software that uses it being actively used I would maybe not worry myself too much about sticking to the original API? Graphics tests much of the GXR functionality comparing it with doing the same operations manually.
by jgharston
Tue Nov 28, 2017 12:35 am
Forum: other vintage computer hardware, software and games
Topic: Lynx Computer
Replies: 11
Views: 675

Re: Lynx Computer

jonb wrote:You could fit an IDE interface.
...
..but you'd have to write a CP/M BIOS. Now that would be a challenge...

Ok. http://mdfs.net/Software/CPM/SmallSys/
:)
by jgharston
Mon Nov 27, 2017 4:16 am
Forum: acorn atom
Topic: Acorn Atom Econet
Replies: 14
Views: 540

Re: Acorn Atom Econet

We did some testing of these utilitie4s at ABUG last week and they didn't work. A brief look at the code showed them to be making direct JSRs into the middle of the Econet code. I've disassembled them and enough of the Econet ROM to find out what they are trying to do, and it's fairly clear that the...
by jgharston
Sun Nov 26, 2017 3:36 am
Forum: hardware
Topic: read / write to JIM
Replies: 36
Views: 967

Re: read / write to JIM

I also came to the same conclusion as you, any software that uses JIM should set all the latches to a safe address afer using them, and the address that is safest across all possible uses is zero. If there's no RAM copy of the paging register(s), what about interrupts? Yes, that's a problem, which ...
by jgharston
Sat Nov 25, 2017 9:36 pm
Forum: hardware
Topic: read / write to JIM
Replies: 36
Views: 967

Re: read / write to JIM

My difficulty with this is that it is never future proof. If I come along with another hardware board that usess FCFC as another paging register this stops working. It's the resetting everything to 0 _after_ use by software that knows how many paging registers it had changed (and disabling interrup...
by jgharston
Sat Nov 25, 2017 9:15 pm
Forum: software: other
Topic: BBC Basic for Z80
Replies: 24
Views: 841

Re: BBC Basic for Z80

Acorn DFS and CP/M both treat double-sided disks as two single-sided disks, No they don't. Acorn CP/M treats a double-sided disk as a single logical disk with 160 tracks, exactly the same as ADFS. CP/M drive A: is both sides of drive 0, CP/M drive B: is both sides of drive 1. The only oddity is tha...
by jgharston
Tue Nov 21, 2017 1:47 am
Forum: upcoming and recent events & exhibitions
Topic: ABUG EAST MIDLANDS (Winter Warmer) 17-19 November 2017 (Leicestershire) BOOKING THREAD
Replies: 139
Views: 5443

Re: ABUG EAST MIDLANDS (Winter Warmer) 17-19 November 2017 (Leicestershire) BOOKING THREAD

sPhilMainwaring wrote:Some more Clwyd Technics references are here:
http://phils-place.co.uk/work/

Ooo. Talking about head-mounted finglongerers, watch closely from 2:40 into this video :)

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