rbourass@udenva.UUCP (01/24/87)
I want to thank every one who responded to
my plea for help with the RS232 Pak. Through
your comments I have the PAK and DRIVE working
together on my Y-CABLE with PIN 8 connected.
I am curious as to why Rainbow suggested
otherwise...
By slightly modifying the RS232 PAK
it can be adapted to work with a
Y cable and disk drive.
Removing the ROM chip (U3) eliminates
the memory conflict between Disk BASIC
and the Pak ROM. ***Cutting the wire
jumper connecting pads E1 and E2
separates the IRQ of the ACAI from
positions 4 and 8 of the cartridge
connector***.
***If the jumper is not cut, any data
input causes the IRQ to become active
which triggers the non-maskable
interrupt and the cartridge inter-
rupt detection input of the computer.
When the CART Pin is active, the
computer resets. If you have the
disk controller connected, the
computer shows the opening credits***.
I am sure the entire problem could be my interpreting
of this article, but I would really appreciate it if
someone well versed in the hardware area could explain
this to me and tell me if there are any other modifications
I should make to insure that I have no problems.
I just can't afford the multipak, even at its sale price.
I also believe there are probably some other people
interested in the RS232 PAK that are too shy to speak up,
so it might be a good idea to post the explanation on the
net rather than just sending it to me. Either way will be
greatly appreciated.
Thanks again,
Rich
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rbourass@udenva 2270 S. Race #610 RBOURASS@DUCAIR
Denver, Co 80210
303-871-5173pete@wlbreng1.UUCP (01/27/87)
Re: the 232-pak pin cutting issue again...
The note you included in your last posting said that the jumper in the
PAK connected the 6551's IRQ line to the NMI line (BTW, was that an
excerpt from RAINBOW??).. well, not REALLY. Originally they had
intended to use the NMI line... if you'll look very closely, you'll
see that the trace to the NMI pin (was it 6??) has been cut, and
that the jumper actually connects to the FIRQ pin (pin 8).. This is
seen by the system as a CART interrupt. Regarding your setup (ROM
removed, but pin 8 left intact) - all is well. Glad it all worked out
for you..
--
Pete Lyall
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