Summer 1979, Issue 3

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Hardware expansion is made standard by the use of NASBUS. This is a bus standard, and this means that the signals between all different expansion boards will meet this standard. Note that the new NAS­COM 2 computer plugs directly into NASBUS, without the need for a buffer board, which is an improvement. The NAS­COM 2 still has the same screen formatting and the same Z80 CPU, so it is highly compatible with NAS­COM 1.


I hope that the article on monitors (later in this newsletter) explaining the development which has resulted in NAS-SYS, has answered many questions. Here is a brief summary. The following group of monitors are all highly compatible.

NASBUG T1: This was replaced by T2, and no one has a NASBUG T1 any longer. (We hope!)

NASBUG T2: Standard 1K monitor.

B-BUG: 2K monitor, fully compatible with T2. It will run all programs written for T2, without modification. It can read and write tapes in LOAD/​DUMP format, like T2, or in READ/​WRITE format. This monitor is not a NAS­COM product.

NASBUG T4: 2K monitor, improved version of B-BUG. Same comments apply as for B-BUG, One tiny difference – SRLOUT routine was moved by one byte.

NAS-SYS 1 This new monitor is not directly compatible with the earlier monitors. It is called NAS-SYS, meaning NAS­COM OPERATING SYSTEM, and has in fact been designed to provide for easy upward compatibility in the future. Quite a few earlier programs have been converted to NAS-SYS, (even including the 8K Basic!), and it has proved very easy in every case. When NAS-SYS and its full documentation and listing are available, I am sure it will be generally agreed that any inconvenience is made worth while by the enormous improvements. If a user has a large number of old programs, an old monitor can always be plugged in to run them. In fact, even NAS­COM 2 could be run under NASBUG T2, if you really want to do this! In the future, all programs will be NAS-SYS compatible, and there won’t be any problems.


The 2K Tiny Basic runs under NASBUG T2, B-BUG or NASBUG T4. If NASBUG T2 is in use, programs are saved on cassette using LOAD/​DUMP format. If B-BUG or T4 are plugged in, then the Basic automatically uses READ/​WRITE format, which is, of course,


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