Copter
Short program.
Sinclair ZX81
4 Home Finance Programs
Income averaging, mortgage payments, auto loan, and interest analysis. 1K.
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Solo Dungeons
Dungeons and Dragons inspired program that featured sealed letters for special rooms. Available as a listing.
Awari
Awari is an ancient African game for two players. Six piles of three stones each are arranged in front of opposing players, with each player’s “home” to the right of the piles. The play consists of taking all the stones in one of the player’s piles and, moving counterclockwise, dropping one stone in each pile
8K Memory PEEK
This slow but simple program peeks memory 100 bytes at a time. It displays consecutive bytes in 5 columns by 20 rows. Designed for the ZX81, it works with 16K RAM.
Sinclair ZX81 ROM Disassembly Part A: 0000H-0F54H
Ian Logan has disassembled and annotated the ZX81 Monitor, easing your access to the improved 8K ROM.
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Salary Scheduling Cost Computation
This 8K/16K program computes salary schedules for two or three classes of teachers (or other workers). For a two column schedule, enter all zeros for the prompts about the third class (Mast+). At the end of the second column, it will ask if you want another. Enter NO and touch NL. The computer will give
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Nuclear Decay Simulation
A popular lab exercise uses special dice to simulate radioactive decay. Marked die faces show the decay probability. After shaking and throwing the dice, replace those with marked sides showing with spheres (stable atoms) or dice with different decay probability (radioactive daughters). Use over 200 atoms for a smooth graph. This program throws, examines and
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Loading Problems with ZX81 Kits
If you have loading problems with a kit ZX81, see if you cracked C10 during assembly. Some machines LOAD fine with 1 (or 2)K internal memory, but not with 16K.
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RAM Decoding for ZX81
Last March we published Al Salt’s plans for adding external RAM to ZX80s. To adapt his Build Additional RAM (SYNTAX 02/03/02) with ZX81s, you can take ne of three approaches. The second two of these plans do not require you to modify the insides of your ZX81.
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Dear Editor
Sinclair discontinues tech support. Inventory control program sought. Connect full size keyboard to ZX81. Improving ZX80 cooling.