Cello wrote: ↑Tue Nov 22, 2016 7:28 pm
On building your own RS232 connector for the PC-3000
...continued
(see also previous posts in this thread)
In my never ending search for some common piece of PCB that fits the proprietary thickness and pin spacing of the serial connector of the PC-3000, I had a Eureka moment and started to check flash memory cards.
And yes, a micro SD card has exact the correct thickness and copper line spacing to fit the PC-3000 connector!
It is one sided though. But if only pin 2 (Receive Data), pin 3 (Transmit Data) and pin 5 (Signal Ground) are needed for a null modem cable, one side should be enough! Can any one confirm?
Would be nice...
Establishing RS232-connection with Sharp PC-3000
Summarizing the issue: the Sharp PC-3000/3100 can not read ordinary PCMCIA memory cards without a special driver. This driver is available but is not included by Sharp on the machine so it has to be transferred to the Sharp via an RS232 connection. But the RS232 connector and cable on the Sahrp is proprietary and that cable can not be found anymore. What to do?
Hence, I tried to make my own connector. After searching for 3(!) years I finally found a connector (from an Apple G5!) that has the correct thickness, number of pins and pin spacing as the Sharp connection. This connector is one side only though but that should be all right since the RXD, TXD and Ground pins are all on the upper side.
Test:
Gear at disposal:
1. PC-3000 with Sharp custom builtin Laplink 3 software and RXD, TXD and Ground pins hand wired to RS232 female connector
2. RS232 cable
3. RS232 null modem cable
4. 2x MSDOS laptop with default Laplink3 software + terminal emulation software (Term90 from Norton Commander)
5. Arduino board wired to RS232 male connector (MAX3232 RS232 to TTL Serial Port Converter Module) and connected to PC. Characters sent and received can be read by Arduino Serial monitor software on PC.
What works:
Laplink3 to Laplink3 between the two MSDOS computers
Term90 to Term90 between the two MSDOS computers
Term90 on a MDOS machine to Arduino and vice versa
What does not work:
Laplink3 on Sharp to Laplink3 on MSDOS computer
Note:
Laplink3 on Sharp to Arduino sends characters one by one but not to be interpreted. These characters differ from those send by Laplink3 on MSDOS computer to Arduino.
So I did a simpler test: see whether I can send some character(s) using DOS piping to COM1 with one of the following commands and read them in Term90 on the receiving machine:
echo hello > com1 ("hello" or any other string of course)
copy t.txt com1
typ t.txt > com1
print t.txt > com1
This worked using any of the two MSDOS machines as sender or receiver, but NOT with the Sharp PC-3000 as sender. That was a great disappointment and I had to give up my research.
Note: using "ctty com1" on the receiving machine neither worked, which was a pity because the Sharp does not have a Terminal program but does have the "ctty com1" command.
If anyone has a hint how to solve this, I'd be grateful.
PS: the proper MODE commands and communication settings in the terminal software were used.