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F.G. Kaal

Member Since 25 Dec 2013
OFFLINE Last Active Today, 11:58 AM

Posts I've Made

In Topic: Using the RS232 DSR

Tue Feb 12, 2019 11:56 AM


I am game for locating the 16550 character i/o routines in the NanoPEB ROM, if Fred Kaal did not already reverse engineer them.


No sorry, I don't own a NanoPeb V2, I only have a V1. I have used a 16550 for one of my early DIY HDX devices though. If somebody has a nanoPeb ROM dump I can have a look.


Fred ;-)

In Topic: Debugger cartridge? Suggestions please

Sat Feb 2, 2019 5:13 AM


I need a monitor/debugger program that can fit in an 8k rom (maybe more.)
Any suggestions for source code to such a thing?  I have TI's RSBUG source code for starters.
I need the usual things like M)odify memory, C)RU, E)xecute.
Ideally I would incorporate the Line-by-line-assembler too. Is there source for that out there?
I've been living out of Mini Memory Easy Bug, and 32k, and would like to cobble together a 8k debugger utility cartridge.


Just for fun I disassembled the Line-By-Line assembler 3 years ago because I wanted something like this to run in the E/A environment. I have added comments and did the bugfixes as suggested by Stuart Conner. Maybe you can use this.


PS: Interesting technique how all opcodes are stored in some kind of compressed table.


Fred ;-)

In Topic: PAL Repository

Fri Nov 23, 2018 5:16 AM

Did some investigation: It is unnescassery for the READY output of the speech synthesizer to go through the PAL or GAL. The speech synthesizer allready has an open collector output (transistor 2N3904) and the READY input of the console has a pullup resistor and is meant to be driven by open collecter outputs.. Have read the manual of the GAL compiler from 1991 ... no signs of any device (PAL nor GAL) that have an open collector output, it is either normal, three-state or registered. Lot of information about the speech synthesizer can be found at Thierry Nouspickel's site (off course): http://www.unige.ch/...ti99/speech.htm

In Topic: PAL Repository

Thu Nov 22, 2018 4:58 AM

It would definitely be good to know, Fred, as that way I can do a new layout for a Speech-in-the-Box board.


Pinout and formula's are in my first message.


The reason that I don't use the GAL20V8 to drive RDYO is that it has to be an open collector output ... I don't know how to program that (yet) for my 1990 GAL compiler.

           |     V     |
   DBIN [ 1]           [24] Vcc
           |           |
    AMC [ 2]     G     [23] MEN
           |     A     |
    AMB [ 3]     L     [22] LED
           |           |
    AMA [ 4]     2     [21] SBE
           |     0     |
     A1 [ 5]     V     [20] DIR
           |     8     |
     A0 [ 6]           [19] A5Out
           |           |
     A3 [ 7]           [18] A15Out
           |           |
     A2 [ 8]           [17] G
           |           |
     A5 [ 9]           [16] RDBENA
           |           |
     A4 [10]           [15] RDY0 (not used)
           |           |
    A15 [11]           [14] RDYI (not used)
           |           |
    Gnd [12]           [13] NC

In Topic: PAL Repository

Wed Nov 21, 2018 12:47 PM

It would definitely be good to know, Fred, as that way I can do a new layout for a Speech-in-the-Box board.

Programmed a GAL20V8.


A have two of those RAVE 99 speech in the box cards.


The first one is original and tested this with the original PAL20L8 which works fine off course but with my GAL20V8 the TI system hangs.


The second one must have been in my Geneve system in the 90's because the 7805 voltage regulator has been removed. Also pin #14 end pin #15 of the PAL is not conected but these pins are connected together on the PCB. Tried this one on my TI99 system and there were problems, also the speech synthesizer thought so because every CALL SAY() gave me as much UHOH's as characters in the phrase.


Replaced the PAL20L8 by the GAL20V8 ... same result, the speech synthesizer only want to say UHOH. Then I saw that the databus buffer chip was a 74HC645 on a socket, replaced this one for a 74HCT245 and now the speech syntheziser can't stop talking (HELLO, #TEXAS INSTRUMENTS#) so I switched of the system ... my poor ears ;-)


Result: The above code for the GAL20v8 does work, but pin #14 and pin#15 of the GAL must be outside of the socket and these pins must be connected on the PCB.


This has something to do whith the RDYO and RDYI signals.