Dear Editor, I offer the following change to Jack’s Fat Mscript, in order to make it work with the Tasman interface version. Change line 15 to read:
15 SAVE "MSCRIPT"CODE 36608,8306Lee Bennett
PO Box 67, Lumber City, GA 31549
Dear Editor, I recently bought a 2040 printer that would not work with my 16K Memotech Rampack. I understand that by removing some capacitors from the printer, it will work. If so, will it not work with other Ram configurations? If it is alright to remove them, what is the easiest way?
Jeff Damerst
[address omitted]
The easiest way to perform this capectomy is with toenail clippers. Remove the screws from the bottom of your printer. Expose the circuit board and locate the controller chip in the back left corner where the interface wire harness enters. The three caps in question are C4, C5 and C6. They are small tan colored caps. Start clipping. These were initially for FCC requirements. Their absence will not interfere with your computing (just your neighbors TV).
Dear Editor, I noticed that my subscription is about to expire, so I have sent a check to renew. The usefulness of your publishing effort is almost beyond description. Sometimes it is a little too technical for me, but I am amazed at how I grow into it. At any rate, it surely provides new computing and engineering frontiers for me.
Phillip Stevens
[address omitted]
Dear Editor, …. I wish Clive would devote more time to creating silicon masterpieces. I think that he could accomplish more by continuing to make it possible for more people to be able to use electrons to move their minds instead of their bodies. Do you know what he is doing these days?
Bob Falk
[address omitted]
As a matter of fact, he is in the process of selling out his share of Sinclair Research to a Czech magnate. I guess his car is not doing so well. We do wish that he would spend more time on support, but then again we will be here for a long time to come.
Dear Editor, In SWN 2/2, On Loading, by Ed Shaughnessy, after the report code C/190 is given in the Save the Un-saveable, it is possible to List the Un-listable. All Ed needs now is a program for Programming the Un-programmable!
Tom Laffin
Box 133, Hillsboro, NH 03244
Dear Editor, The Forum column article on Spectrum compatability should prove to be useful to most of your readers. You seem almost apologetic in saying that the use of 10K pullup resistors is a “quick and dirty” fix. In my opinion this is the correct solution. Furthermore, since the data lines are at the expansion connectors, there is no need to open the case to install them.
The keyscan differences of the two machines can cause problems, but most of the software has already been corrected for this. It is the interrupt programs that are most interesting. In Mode 2, the Spectrum does find FF on the bus, but in the 2068, I have found 0F, 2F, 3F, 0E and there may even be others. Some programs don’t need an emulator, they need only pullup resistors. One problem that even this won’t fix is the speed/TV scan difference. Some programs require a set of calculations to be completed between TV scans. Some Spectrum software may not keep up with the frantic pace of the 2068.
Wes Brzozowski, Sincus News and User Group
[address omitted] [phone number omitted]
Thanks, I needed that. Wes has a lot more information on this. Send him a SASE and he will fill you in on all the details.
Dear Editor, I plan to try Fred’s Load Amp circuit (SWN 2/5) soon. He mentions that one 2068 from GTLB had a single diode bridging the two cascaded ones (CR25 & CR26). I wonder if Timex had come up with the same cure that I did for fried SCLD chips. I believe that that single diode was reversed from the other two. This would give a clamp of no more than -.6V. He also mentions that this computer did not have one of the caps that the others had. This would stand to reason, as a boost in signal strength could be tolerated by the SCLD if it is clamped with the diode to -.6V. I suggest that anybody installing any device to increase the load signal, should add this reverse diode for protection. (Fred agrees. If one of the other diodes goes, you could have problems.) Since the SCLD is a CMOS device, I doubt that it has a comparator in the load circuitry. The Spectrum has schmitt trigger input, and I would say that the 2068 has a CMOS version of this.
As a matter of interest, I expect to have the disk “B” boards by the end of July. All I will need to make the system fly will be Ray’s DOS and the DOCS.
John Oliger
11601 Whidbey Dr., Cumberland, IN 46229
Dear Editor, In the Print Command Compiler, on the last page in SWN 2/5, you have the 18 byte disassembly incorrectly listed. You have the HL register loading from and to the variable “prog” (5C53h). Although it doesn’t matter, the correct variable should be “ch_add” (5C5Dh). It may confuse anyone studying the listing though.
William Powers, Maxsoft
611 Franklin St. Hamilton, OH 45013