Spectrum Computing

10 IF NOT USR 82 AND USR 0 THEN PRINT "BOO!" "USR 82" is just a ret, and returns 82. if short circuit is on, then nothing will happen. otherwise the Speccy will reset. ;-) You can try the program below if you prefer not reset your machine. :-) 10 IF 1 OR 2/0 THEN PRINT "OK&...

edjones wrote: ↑Sat Mar 04, 2023 11:35 am Seems keybase is no more and SpecEmu lives here atm:
https://1drv.ms/u/s!AmOOhLw8lDDyhYYr4AAs2_mKFGtn6Q

I cannot download, the message says the file isn't available.

After DisassemBASIC , a 100% pure BASIC Z80 disassembler, I'm releasing now TK Disassembler , written entirely in Z80 assembler. ;) https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUtRlbLv6IlnZstoLSqxT5peu8sWpI6yji4m1B061GZtMrR4R_PkbZEFxhcThBt6dsXJdwYINeDzUZSZO7NAbhZOP58A1NoZBi4m1pHLFjp-W...

Nice work. Obvs it's not going to replace a PC disassembler, but it's fast enough to keep pace with reading line by line. If I had to, I could make use of this. It's a lot faster than this type-in disassembler for example. I suspected that there must already be a disassembler in BASIC, but I didn't...

Is it possible to write a Z80 disassembler in pure BASIC? Yes, it is possible and it works perfectly. The only downside is the speed of Spectrum BASIC. :) https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggRKJxgfABkHCHwCFiHQqMZropCCSLWd2WXbx9dHUV_-LUyiFwrVDsEWU4wn9g99ptzKQ6s8wFt7za8UxtDKe9...

All Opcodes is a BASIC program that generates all opcodes for Z80 CPU in the Spectrum RAM. You can see all Z80 instructions in your favourite disassembler/debugger. https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOHCRWWjmjpBbr_v0dAcekViOobna9QYfu07_7_V6otGzGzNxSe7Ous_eEAldqw34XW9VB_YDjH...

Spectrum Analyser is for Windows but I use only Linux (Debian testing). I tried to run with Wine and was unsuccessful.

I disassembled the ROM of Romantic Robot Multiface 1 . The zip archive containing the disassembly listing can be download from Google Drive. The link is: https://drive.google.com/file/d/1JLH_fYa4NuvIoZkW6_2aQVkyuJU237xN/view?usp=share_link It is a plain text file, can be viewed/edited with any text ...

Thank you for the reply, I’ll stick with what I’ve got for now, it’s to animate UDGS I currently only have up done and that’s 112 bytes. So down, left and right will be a further (approx) 336 as an absolute minimum. I'm not sure if I'm following you. Poke some hundred bytes uses a lot of time, I'm ...

This question is not easy to answer. Probably peek/poke is more efficient if each element is 1 byte long. Multiple peeks/pokes to handle only one element would be slower, I think.

@Luzie
Nice! Glad to know that at least one person abroad knows Explorer. Anyone else maybe?
Yes, I'm owner of Cantinho do TK90X blog and I know Trucco (I helped him a few times before). I've been in a long hiatus, know I'm back to the hobby.

I noticed that nobody outside Brazil knows this interface. Explorer is a Brazilian interface with AY-3-8912 sound chip. It gives Spectrum 128 sound capabilities to TK90X, TK95 and Spectrum 48. It works like Melodik , but the schematics are not the same. I bought mine in 1990. The interface is housed...

It looks like a 48K and not like a 48K at the same time. Is the text translated into Portuguese or is it still in English? Microdigital cloned ZX Spectrum 16/48 in 1985 and modified the ROM to support Portuguese and Spanish languages. The error messages are translated and some characters with diacr...

Mpk wrote: ↑Thu Jan 05, 2023 4:07 pm I have to ask - what does the Magic Button do?

The Magic Button saves a program snapshot to a floppy disk. That interface is a Brazilian clone of Technology Research Beta 48 disk interface made by Synchron. It is not a clone of Beta 128 interface that was very popular in Eastern Europe.

PeterJ wrote: ↑Thu Jan 05, 2023 4:01 pm Thanks for the photo. Can I ask what the 'TK Explorer' is?

Explorer is a Brazilian interface with AY-3-8912 PSG chip. This add-on gives Spectrum 128 sound capability to TK90X/TK95/Spectrum 48. It resembles Melodik interface.

Hi! I subscribed to the Spectrum Computing exactly one year ago, I think this is a good time to introduce myself. ;) I live in Brazil and my first computer was a CP200, a Brazilian clone of ZX-81. At that time, Brazilians were prohibited from importing computer products. My next computer was TK90X, ...

all I remember is that the 18 year old me tried to select a 3 byte sequence that didn't make sense as character codes or assembly instructions and was unlikely to appear as graphic data. Do you think I succeeded with 37h, EDh and CBh ? I believe so, I don't remember any titles that were impossible ...

@Turtle_Quality

Do you remember how you got that 3-byte marker? Just for curiosity.

Wow! It emulates TK90X and TK95! Very interesting indeed!

https://lh3.googleusercontent.com/y_h5vWV364_P4Fkkiyk8QMPfkWt97AOkzD1WyQEWWNofvZwtGRrVB3l_uk4TBlTGhJUMbnm3J0Oobub6c9oTsJM9rVGLWkoNbM-4O0gSs8jacBdvCQW5kIE_b92bC-KYNsANsx5JaYM8AnTI-j9DyuA_Z4xnpI7RPgMSdjzBgaCD72eIfKnpiT1eufNiWqDzt0XEiEabImQwH68spgpC_wjgo0CYImJk07dohIaYI66NJP7HiZe9nPK_5ijkgQ2Hs1i0ojMeI...

Thanks @tkfan it's a well commented disassembly As I mentioned before I was concerned at the time that someone would realise and be able to to prevent MF1 backup due to to a vulnerability in my compression code, but to have it discovered after 38 years was the best Christmas present I had this year...

Yes I know, I wrote it many years ago. I had suspicions that someone in the world should know about this, but I couldn't find anything on the web. I'm curious, where did you publish about your discovery? :?: Anyway, this is how I remember it... did you manage to disassemble it @tkfan because I'd lo...

The Romantic Robot add-on, Multiface 1, made any software protection almost useless at the time. However, I found that if a sequence of three bytes (in hex) 37h, EDh and CBh is placed in video RAM (16384-23295 or 4000h-5AFFh) or in any address above 25264 (62B0h), the attempt to save the program fai...

I own a Brazilian Multiface One clone, I don't know if it is an exact copy of Romantic Robot original hardware. In my hardware, IN 159 (9F hex) pages in MF ROM & RAM and IN 31 (1F hex) pages in Spectrum ROM. A 74LS74 latch is used to select what ROM are enabled.

What about setting error handling procedure, and intentionally create error situation to run it? Or even LOAD "" CODE can run machine code without USR, if cleverly used. Despite one can run machine code without USR, I cannot see such tricks as a real support for programming at CPU level f...