Ultimate Play The Game : Pentagram - WIP port release for the Atari 8bit


Although I am not a fan of the Ultimate Play the Games, even if they still do have a huge cult following with some titles going over £100 on Ebay. We couldn't help but notice the work in progress Atari 8bit port of ' Pentagram ' which is being ported from the ZX Spectrum version by mariusz and made available since yesterday. Originally released by Ultimate Play The Game in 1986. It is the fourth in the Sabreman series, following on from his adventures in Sabre Wulf, Underwurlde and Knight Lore.


As for the development of this port this has been explained on the main discussion site, but for the purpose of this write up, here is the quote directly . I have used a simple static recompiler which takes Spectrum Z80 code and produces equivalent 6502 code. Created code is slow and unoptimized, but it is mostly working correctly. Recompiler is not designed to produce 100% correct 6502 code, but instead it can detect several situations which require manual intervention, like A register being read by Z80 instruction and not set by previous instruction. Also, I have developed a tool to verify correctness of the code. It runs both Spectrum and Atari versions in parallel using Z80 and 6502 emulators and compares memory accesses (read and writes) of both versions and reports differences. It skips all opcode reads (as these are obviously different) and for memory reads it checks if given address from Z80 version is properly mapped to 6502 version.




Currently this work in progress port is playable but hasn't been tested very much and is slower than the ZX Spectrum version due to un-optimization. However there is hope that it can be brought to better speeds later on, more especially towards a final release

To play the game, use Altirra emulator and run pg.obx. On the title screen, press 1 to play with keyboard and press 2 to play with (emulated) Kempston joystick. Then press 0 to start the game. Other input means (Cursor Joystick and Interface II) are not emulated.

Links : 1) Discussion (Download on forum)

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