Spectrum emulator

Utility

MGT


MGT Graham Mason


One of the selling points used to position the Coupé in the marketplace (which is often debated as both a good or bad move on the part of MGT) was as the upgrade to the ZX Spectrum and thus you could play backwardly compatible speccy games whilst enjoying the new features of the machine.

This meant that MGT had to provide some form of emulation to ship with the machine to allow this.

What users were not told at this stage was that the emulation was for the 48K only and not the 128K machines, in fact emulation of the 128K’s memory map would prove impossible at workable speeds. Simon Cooke began work on an emulator that ran at best at about 1/16th of the required speed although many demos and games were converted manually to great effect by people like Simon Cooke, Stefan Drissen and Edwin Blink.

The original emualtion was via a patched ROM image that was not 100% compatible leading to many problems with software that made extensive ROM routine calls or utilised undocumented calls or features.

Another issue discovered was that getting the software to load at all was an often problamatic due to differences in machine timing.
Many games with anti-piracy software protection loaders like Speedlok and Hyperload would not work at all.

To address this MGT engaged the services of Graham 'Turbo' Mason a well known hacker on the Speccy scene and Your Sinclair’s resident ‘game cheats’ expert to provide workarounds for the loaders.

Users soon found that by aquiring a copy of the Spectrum 48K and a few minor adjustments gave much better emulation results and lists of ‘compatible’ tiltle started appearing in magazines such as Fred and even some games listed themselves as ‘Coupé Compatible’ like Thalamus’s Delta Charge.

Some ‘standard hacks’ to make the ROM operate originally from Format (Vol 3 Issue 5 January 1990) by Ken Elston appeared in many publications including Fred 1 as well as instructions for replacing the ‘skelt.bin’ ROM image from the MGT emulator.

A market then grew for 3rd party Spectrum emulators that offered enhanced features such as superior file handling, correct keyboard mapping and even fixes to the timing bugs intoduced by running on the Coupé and thus allowing games to load without the need for the loader hacks.

Many such emulators were produced with titles like LERM’s SamTape, SC_Speclone and Specmaker leading the pack.

In 1991 SamCo released a hardware solution for transferring data called The Messenger that could send snapshots from the Spectrum after they had loaded, the only disadvantage was that you had to have the Spectrum hardware.

hi

http://velesoft.speccy.cz/sam_zx128.htm
sim coupe 1-4mb external option two on snapper menu last two discs right at end of link no 128 multiface or .kul files as yet…
can anyone remember which fred hada 48 emulator that could handle multiface snaps please?

can anyone figure out how to modify all emulators so that teh top 32768bytes of 48 ram are external 1mb area paged?
might be ok for freescape and vector stuff no?

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.