Audio coprocessor connection test

Hello, All I found in which issue of "Radio Amateur" such a test to check the connection sound coprocessor (I write from memory) 10 OUT 65533.12 20 FOR A=0 TO 15 : OUT 49149,A 30 PRINT IN 65533, IN 49149 40 NEXT A It is written that if everything is connected correctly, it should display two columns of 16 numbers 255. I have KAY-128 (this is Leningrad1+AY+128 KB according to the Pentagon scheme) displays the first column is from 1 to 16, the second is all 16 digits 224. System test 4.30 also says that I am not connected correctly sound coprocessor. But at the same time, the sound coprocessor works in all my games. I looked carefully at the diagram (similar to KAY-256) and checked all the connections - everything is OK, writing occurs at addresses BFFFD, FFFD, reading occurs at address FFFD. True, instead of AY-8910 I have YM2149 installed. Therefore, the question arises, either something is not quite connected correctly, or All these tests are designed for AY-8910??? Or maybe there are some problems with timing... Since for normal operation of the computer I had to install a capacitor 100 PF per 1 output of the 555IR22 microcircuit (CSRAM signal). (installing a 100 PF capacitor on the processor's RD signal also helps, but I I preferred to plug it into the CSRAM signal) Otherwise, the computer is unstable and freezes when switching from 128 KB mode, to 48 KB mode.Perhaps this somehow affects reading from the sound coprocessor??? Although all games work without problems even with a 100 PF capacitor installed on 1 output of the 555IR22 chip The computer works stably for a long time... Who will have any assumptions and explanations?

Hello roma Typically, reading solid #FF indicates the device is missing rather than presence, as well as any reading from a non-existent port. But I'll try that my Pentagon will say :) .

Hello(s), Wladimir...! 03 Feb 06 13:35, Wladimir Bulchukey -> All: WB> Usually reading solid #FF indicates the absence of a device rather than WB> is about presence, as is any read from a non-existent port. But I'll try WB> what will my Pentagon say :) . The first row is numbers from 0 to 15, the second row is all 255. All tests say that AY is turned on correctly, the data bus is not clogged. However, there is one deme (Gift Klim (Moscow Klim, not Rostov)), which says you don't have AY. But this is an isolated case in all 13 years existence of this Pentagon :) . With the best - Wlodek # wlblack()newmail.ru # http://wlodeks.narod.ru [ZX] [500:95/462@ZXNet] [2:5016 Forever] [Golyanovo] [Old Russians]