Spectrum Computing

If you want to call a routine which returns from the calling routine, you can pop and discard the first return address before returning. call FirstRoutine ; SecondRoutine returns here FirstRoutine: call SecondRoutine ; SecondRoutine does NOT return here ret SecondRoutine: ; adjust the stack to retur...

The usual way is to figure out what the entry point address is, abs put a breakpoint there. Snapshots do have a single well-defined entry point, but tape/disk/microdrive programs are not like that. There’s usually a bunch of blocks that are loaded one after the other, often with code running in betw...

Ralf has put his finger on the way that we do it. You can easily have a mix of OR and AND conditions, too. The condition code just threads through a series of checks, one at a time. You don't need to track the state of where you are at within the condition checking in an additional register, the cur...

Ped said it’s unlikely to happen, as injecting multi-line macros as single expression to evaluate it doesn't fit current code architecture at all.

I went a bit overboard, and have this in some of my projects: Black equ 0 Blue equ 1 Red equ 2 Magenta equ 3 Green equ 4 Cyan equ 5 Yellow equ 6 White equ 7 BlackP equ 8*Black BlueP equ 8*Blue RedP equ 8*Red MagentaP equ 8*Magenta GreenP equ 8*Green CyanP equ 8*Cyan YellowP equ 8*Yellow WhiteP equ 8...

I suppose it's not the end of the world to make all your macros emit a single db or dw in front of the expression. And then just concatenate the macro invocations with colons on one line.

ParadigmShifter wrote: ↑Fri Oct 13, 2023 9:38 pm Yeah one of the things I don't like about sjasmplus is that I can't find a way to return an expression from a macro

Yep you can't. I checked with Ped.

I have a ton of zeus macros that do exactly that in the middle of db blocks, and I'm having to rewrite them.

Einar Saukas wrote: ↑Fri Oct 13, 2023 8:42 pm If it makes you feel better, keep in mind that a MOD in ZXDB has nothing to do with modifying. The term M.O.D. means "Multiple Outsourced Datasets"

And of course a RIP means Reciprocally Interchanged Parts"...

I have an absolute ton of macros like that. I used to be a believer in pseudo-instructions imlemented in the assembler; but I changed my mind, and now I run with strict syntax settings and explicit macros for the fancy stuff. I am weaning myself off zeus for sjasmplus, and I really miss that it had ...

If you try to define a string constant with equ it will force it to a very long Int32: I mostly mention this because, if you injudiciously mistype a constant name in a place where it controls the length of assembled code, you can end up with a very long stuck assembly process that's trying to alloc...

PeterJ wrote: ↑Fri Oct 13, 2023 8:35 pm What documents is that screen address image from @ParadigmShifter?

https://www.overtakenbyevents.com/lets- ... art-three/

Sometimes constants are defined with other directives. For example in sjasmplus (and I assume sjasm is the same), string constants are defined like this, and numeric constants can be too: define MY_STRING_CONSTANT_NAME "FooBar" ; define can't be in first column define MY_NUMERIC_CONSTANT_N...

CSpect Plugins v1.5 is released. These are my plugins, not Mike's (which confusingly have the same github repo name). Added Pi UART support to UARTReplacement plugin. Added support for mapping Pi GPIO pins 4 and 5 to serial DTR and RTS. Fixed UART RX slowdown caused by sleeping 1ms every time the RX...

I heard that you could touch the tip of a Speccy RF lead to the aerial, and it would give a passable picture. Obviously not if you’ve done the composite mod.

I am still wondering, why I am the only one experiencing that (or just noticing that?). I have no crosstalk from my Retro Computer Shack cable (although that is for +3 not +2 grey, and his cables for those two systems have materially different passive components). All video wires are untwisted and ...

You can try cleaning the expansion bus edge connector, in order of increasing desparation:

• alcohol and cotton swab (mild);
• eraser (fairly mild);
• Brasso (not so mild)

And check the polarity key hasn't fallen out and the device is being aligned correctly.

The Timex Sinclair models like TS2608 could display 64 columns of 8x8 pixel text on a TV. They had built in RF modulator and built in composite video output. The manual recommended using the composite output in hi-res mode, but it also worked, less clearly readable, over RF. It really depends what y...

It would be useful for emulator authors to test emulators.

jamesh wrote: ↑Wed Oct 04, 2023 6:52 pm What would be a good source of 8-core individually shielded cable? Preferably not a 25m or 100m reel In the UK.

You might just buy a professionally made cable such as this: https://www.ebay.co.uk/itm/260949446667 Retro Computer Shack's cables have great quality and a great reputation.

room1: defb "this room is dark",1 defw room2 This counts as a forward reference. Most assemblers will do at least two passes if they decide it is needed. The first pass makes placeholders for all the values which aren’t known yet, and the second pass fills them in. This can get much more ...

Ah right, gotcha. The YouTube description of that video didn't seem to indicate that it was running on special hardware! The .SCL linked in the video description does run with Pentagon 128K timing and paging, without Betadisk or TR-DOS but with a divMMC running esxDOS and Bob Fossil's browser. It d...

1024MAK wrote: ↑Sat Sep 23, 2023 8:27 pm There’s three possible default actions available with hardware registers

ZX-HD is not really hardware in that sense, though. It’s just a program running on a raspberry Pi. It would be perverse to go out of their way to leave what are implemented as software variables uninitialised.

#CSpect also supports 48K model, divMMC and Multiface 3. Not that you would probably ever choose it as an emulator based on support for 48K/128K or those addons.

TMD2003 wrote: ↑Wed Sep 13, 2023 9:39 pm Chill, Winston

Chill engaged

so anyone who thinks this is Lee's doing is barking up the wrong tree. The only thing Lee is responsible for is the fact that WoS uses a very old version of ZXDB Given that we know somebody created Spectrum versions of these ZX80 listings and the entries were created. happened prior to ZXDB and ZXD...