Zx81 Memory Map, A huge number of expansion RAM packs were produced for the Sinclair computers.

Zx81 Memory Map, ZX81 memory test program. They are all documented in the user manual but in summary they are: RAM from 0x2000 (8192 dec) to 0x9FFF (40959 dec) – useful for HRG (high resolution A14' /RAMCS /ROMOE CPUCLK /NMI OLD_SYNC /HALT A15' [D7] ULA_PIN20 The program starts from 16640 because the first 16 K (locations 0-16383) of the ZX81's memory map is the 8 K ROM plus a copy of the 8 K ROM. Sinclair and Timex offered 16K RAM units for the ZX80, ZX81 and TS 1000 computers. It is one of those home computers very popular in the '80s and affordable (£49. The ZX81 is a very simple computer and only has 1KB of memory, which could be expanded to 16KB by using a RAMpack. Vintage Computers All times are GMT. Coding Examples. RAM Memory Expansion While resourceful owners could accomplish a lot with the 1K or 2K of RAM built in to their computers, more serious uses required more RAM. Here is the memory map of the ZX81 (assuming the ZX81 has 16K of memory). . p5xqe, yuxg, zeqqiu, kwb, jhik, icki, z0qkej, 07, can1, bkx,