z88dk forums

I've been keeping a rather dispersive blog here: https://z88dk.org/forum/viewtopic.php?f=2&t=11860 Only four CP/M BIOS implementations kept the display page at $4000 and require the bouncer subroutine relocation in the CRT0 stub: This post is a first description on what has been achieved so far....

I finally got a reasonably clean merge of the LEC CP/M stuff in appmake, crt0 and config.

the new build option is +cpm -startup=zxlec

The LEC-CP/M. It works even on Microdrives or in RAM Disk on any diskless ZX Spectrum with a modified RAM ! To transfer the programs I set up a specific tape conversion tool, it's in {z88dk}/support/zx/cpm2tap.c mbasic_lec.png This is one of the few requiring only a simple "startup=" perso...

The way I found to page in and out the display is very glitchy but sort of works (the lower display at $4000 is shown while drawing). I don't know if it is possible to avoid it, perbaps the CP/M was avoiding the glitches waiting the display raster retrace ? MicrosoftTeams-image (1).png The original ...

The ASC CP/M was yet another eastern (Ukraine ?) CP/M conversion to the ZX Spectrum developed by Andrew Strikes Code (ASC) and Alexander Shafir. It was designed to work on a memory mod called LSY-256 (with two shadow RAM pages) and the Betadisk controller. asc_cpm.png The disk format is basically th...

The CS-Disk, (Nederlands) This one, like the Dataputer DiskFace, had logic to overlap the ROM with a RAM page in the disk expansion. The BIOS was in ROM (as on the ATM-TURBO) and didn't require a disk to boot. https://upload.wikimedia.org/wikipedia/commons/d/d3/Zx-cpm.jpg So far i couldn't find the ...

I think that having an objective is the best way to ramp up the learning curve. I also wonder if you ever succeeded in building and running the z88dk examples. You could start altering those programs by adding what you are learning. Is also suggest to try another z88dk target, in example the msx. it...

The Timex FDD-3000 CP/M disk format is now supported by appmake. It really is NOT strictly ZX Spectrum related, it runs the CP/M system on the internal Z80 and requires a remote terminal, which can be attached to the RS232 port or to a terminal emulation running on the Spectrum. In this second confi...

Sub functions?
Have you tried with an extra parenthesis enclosure?
Could you show a code snippet?

I prepared a simple hack for the +CPM target, now -subtype=diskface should build a dataputer compatible CP/M program. In the meantime I've been warned that the MBASIC concept I've just announced is buggy and I noticed that also the plus3 mode looks weak. It could be for memory constraints, I'm inves...

Back to the Dataputer DiskFace, it looks like my blind attempt to port MBASIC with graphics on it worked!
This means that the disk format is good and that I can use the paging logic on z88dk.
Ironically this one is the easier to work out adapting the existing code.

Paging basically works, i built DSTAR, It runs with no changes on the current z88dk set.
It crashes on exit though, probably trying to restore the default disk via a BDOS call.

The CP/M 2.2 implementation on the +3 crashes at startup when running any existing version of MBASIC, including the so called OBASIC. It's very strange that Microsoft BASIC was mentioned as one of the working Softwares. I suspect the problem is on the memory assessment phase, but I couldn't track do...

MBASIC concept extended to the ELWRO 800 Junior. D-FILE is at 0xE000 :rolleyes: Color attributes are tricky to work out, they had an extra mini memory bank and I haven't figured out the right way to access it. The text color handling is on the BIOS, easy to hook to the BASIC engine. As said MAME is ...

I've almost finished the list of the ZX Spectrum clones having a reasonably good emulation in CP/M mode. There's still a rebased CP/M by Kamill Karimov which runs on any Spectrum 128 but is somewhat limited. I'm leaving it behind because it will require rebased BDOS calls (6005h), and ORG to be posi...

I succeded in porting MBASIC (it's acting as a test case) to the Profi models on the PINIX CP/M.
(screenshot taken before fixing the default color attributes values)

..and, still on the Profi, the KLUG CP/M.
(this one has been more difficult to track down)

Felix HC-2000 (and possibly HC-91). Display memory paging logic tracked here, too.

A very basic approach could be this. Suppose you are building "examples/console/tic.c": zcc +zx -lndos -create-app -a tic.c ren tic.c.asm t.asm (Edit t.asm ..) zcc +zx -lndos -create-app t.asm This is an easy starter for some early experiment, you still get the libraries linked in and pack...

Using C compiled code and making it relocatable sadly has many other aspects to consider which make the jr topic less than relevant. There is a way for getting relocatable code (which you might not like, I'm afraid) or you could simply dig out the assembly source, use search/replace on an editor and...

The Quorum-128 has an extra memory paging register (80FDh) used to enable/disable write access to the background RAM.

You probably did, but can I ask if you downloaded the right z88dk-src-2.3.tgz file ?

I'm asking because there is a possible confusion: "Do not download the autogenerated "Source code" files at the bottom - they are missing dependencies and won't compile correctly!"

you have also something in the core routines getk() Ia the universal way to do it, but it is very primitive. On many targets it won't stop the ruining program but will suffer for collisions in case of multiple keypresses. By the way a nonzero result means "any key". joystick() covers also ...

Disassembling a simple graphics demo for the Scorpion was the easiest way to begin. The video memory on the Scorpion is placed at $C000, no need to relocate VPEEK/VPOKE. zxs_basic_circle.png EDIT: the MBASIC experiments are a good intermediate step before touching the libraries. The Russian clones h...

..and after getting most of this sorted out (especially the past work on the PCW format) I found this document: https://www.seasip.info/Cpm/amsform.html CPC system This simple system is used by CPC computers: If the first physical sector is 41h, the disc is in System format, ie: single sided, single...

In short, apparently the only missing disk format was the German "Vortex" one. I tested it on WinApe, putting the Vortex20 ROM on the upper slot #6, mounting the proper system disk and booting it with "|cpm". We now have a lot of target formats for the CPC, the ZX Spectrum and th...