Comments on Dr. Watson’s Bankswitching Article

In the previous issues of LIST you have seen the contributions of Bill Pedersen concerning Bankswitching on the TS2068. I had a long phone conversation with Bill, and asked him to provide LIST with a comprehensive culminating article to the series. Let us hope that he finds the time, and writes an article which will integrate the concepts he presented, as well as tie all the loose ends in his proposed approach to the design of the Bank Expansion Unit (BEU).

In the last three issues of TIME DESIGN Magazine, Wes Brzozowski published an intriguing series of articles titled ”The Mystery of the Missing 253…”. Wes has done an excellent detective work on the code of the TS2068 to unravel the mysteries of the hardware architecture of the BEU.

Recently we at LIST were lucky enough to receive a long article from Dr. Watson(?) concerning the intentions of the design team of the T/S 2000 series computers. We here at LIST realize that some of the information in Dr. Watson’s article was superceded at the time when the TS2068 was released. We still think that information is still relevant, i.e. it is not a nostalgic look backwards for what might have been if……. The information is especially relevant as far as the the System Configuration Table (SCT or SYSCON), and in explaining the code of the ID block in any of the expansion banks is concerned. The article also sheds light on channels and streams, and the buildup of RAM tables for dumb and intelligent devices.

The article as we received it was too long to be presented in a single issue of LIST. So we split it in two parts. The second part will be published either in the March ’87 or April ’87 issue of LIST. The second part of the article will explain the function dispatcher, and all the missing and reserved codes which appeared in the TS2068 Tech. Manual. As such, the article is an excellent addition to your Tech. Manual.

It is noted that in Wes’ articles in TIME DESIGNS, there were question marks and misinterpretation of SCT entries. Dr. Watson ( in a small note accompanying the manuscript) expressed the hope that the article will fill the gaps, and correct the errors.

The envelope in which the article arrived, did not have a return address. Cosidering that Dr. Watson is 145 years young, it is no wonder. In the small note accompanying the article Dr. Watson expalins that information was relayed to him by Inspector Hitherton of The Scotland Yard. It seems that The Scotland Yard and Mr. Holmes were cooperating on a case known as ”Now you see it, Now You Don’t’ Computer Division of TIMEX_Ltd.”. For that matter at the time of information relay to Dr. Watson, Mr. Holmes was on an overseas sojourn, somewhere in the Iberian Peninsula, investigating certain anomalous investment patterns by the said company.

In order for our general readership to benefit maximally from Dr. Watson’s contribution the following reference material is suggested.

• “The Mystery of The Missing 253…” by Wes Brzozowski, in the last three issues of TIME DESIGN Magazine.
• TS2068 Tech. Manual.
• ”Bankswitching the 2068”, by Ray Kingsley in the Jan.-Feb. ’85 Syneware News.
• For the Function Dispatcher ( to be published) you will need ”A Comparative ROM Atlas- From Spectrum to TS2068” by N.A. Pashtoon, in the Nov. 1984 issue of SYNTAX. The same tables were also published in LIST: Jan. ’85 to Apr… ’85.