TRS-80 Model 4 and the (presumed) missing ext. drive port

[KirkJT]

Hello there,

my name is Marco, I'm from Italy and just joined both this forum and the community of TRS-80 owners.
I'm totally new to the machine but getting fast to deepen my knowledge about programming it.
As many latecomers I struggled to bring old software found on the web on 5.25 floppy disks and decided to buy an HxC emulator (which is set to arrive in the next couple of weeks) to connect as the third drive to be kept external. While waiting for the emulator to arrive, I had a look at the best way to connect it to the Model 4 and got a big question mark floating over my head: where there should be a PCB connector under the chassis I just have a hole (photo here below)! I'm pretty sure the machine has not been modified, yet the connector is not there. Moreover the general port layout is different from that depicted in the manual. Am I missing something?

here what I should find according to the manual


and here my layout


as you can see the hole is just... a hole.


Also, I'm struggling at finding a clamp-on PCB connector for flat cables (it seems nowadays they just have tons of IDC ones); where did you buy yours?

Thanks in advance for any help.

M.

[gonk23]

You've got a newer "gate array" model 4, where the floppy drive controller is integrated on the motherboard. I believe the 34 pin port at the top of your photo is the external floppy drive port.

For the connector: if you search google or ebay for "34 pin edge connector" you may find a few.

[KirkJT]

You've got a newer "gate array" model 4, where the floppy drive controller is integrated on the motherboard. I believe the 34 pin port at the top of your photo is the external floppy drive port.

For the connector: if you search google or ebay for "34 pin edge connector" you may find a few.

Thanks a lot, I'll give it a check tonight.
So, it seems to me that gate array models also have the RS232 facing backward rather than downward as a clue. I was told that looking at the cursor keys (clustered or non clustered) would have been an indicator of the type of model and got totally biased in my inspection.

Best,

Marco