Available RAM Gauge

A preview of the program in action.
   
Author's name: John Mark Mobley
Author's web site: none given

Description:

This program identifies how much RAM is available for programs and data.

Full Screen Expected Results:
Sinclair ZX81 1K RAM: 0 bytes free
Sinclair ZX81 16K RAM: 15100 bytes free
TS1000 ...... 2K RAM: 800 bytes free
TS1000 ...... 16K RAM: 15100 bytes free

Cleared Screen Expected Results:
(Remove lines 30, 40, and 50.)
Sinclair ZX81 1K RAM: 500 bytes free
Sinclair ZX81 16K RAM: 15100 bytes free
TS1000 ...... 2K RAM: 1500 bytes free
TS1000 ...... 16K RAM: 15100 bytes free

Lines 30, 40, and 50 of the program fill the display file (video text RAM / screen buffer) with (32+1)*22=726 bytes of RAM. A 1K RAM system (such as a Sinclair ZX81 computer without a RAM expansion module) will stop with an error report number 4 before the screen is full. One option is to press <CONT> and <ENTER> after error report 4 appears on the screen. Another option is to remove lines 30, 40 and 50.