26

I did that all the time on the Apple II. The reason it worked was that some time was needed for the motor to spin up to the correct speed, and that the Disk II didn't really have an "eject" mechanism, but that you could very directly mechanically lift the read-write head from the surface of the disk. That meant that if you were quick enough to lift the ...


19

Since when do kids need a reason to trashtalk? Especially with an abbreviation calling for such an interpretation? And fans of competing computers where even more eager to jump the train. The war didn't start with Amiga vs. Atari ST :) But (a bit more) serious, there was also a real reason for this name: Early Model 1 where already on itself rather ...


16

Theoretically, yes. The disk needs time to spin up to speed before reading or writing can occur. While it varies between platforms and drives, it's at least a couple hundred milliseconds. That's arguably just enough time to realize you shouldn't have hit enter, and to pop the drive latch. Especially if you subconsciously realize it before you even hit ...


12

The Model 1 was a self contained computer that plugged in to, essentially, a TV set. And that was all well and good, if feature light (16K RAM, Cassette port, limited text and graphics). But it was plug and play. The original version, w/4K and Level 1 BASIC was notorious, for example, for key bounce. You could buy a simple mod to fix it, and it was remedied ...


10

OK, this is very dusty material in my memory, so I'm relying a bit on Google/Wikipedia here. I may be able to find some of my printed documentation, but it will take a while. The granule was the allocation unit for the filesystem. I don't remember the granule size on single-density drives, but Wikipedia says for double-density drives it was 6 sectors per ...


7

ROM BASIC does not support any handling of floppies at all, but System ROM allows boot thru it's function table. Of course one could handle the disk controller 'manually' from BASIC - which is what the example does. Routines (All following values are according to TRS‑80 ROM Routines Documented) The System ROM (3000h-37FFh) only supports booting a disk. There ...


7

I got the same result -- it's a bug. It does work at low-baud rate so you can use that as a workaround. Type L when the Cass? prompt appears at startup. Looking at the output file the emulator is only saving the sync header of the saved program. I tried this version 1.28, the most recent as of this writing. I'll send a bug report.


5

I can tell you as a former Radio Shack employee, we used to call them that as well. That said, I am happy with my still functioning, very modified Mod I.


5

The TRS-80 Model III is a pretty robust machine but there is one common problem -- the RIFA capacitors on the power supply. These were paper-type and very often short out producing lots of smoke though generally don't cause any damage to the machine itself. There is an excellent page devoted to that procedure: http://www.akhara.com/trs-80/psrepair/index....


4

First, do a visual inspection. Make sure it's reasonably clean, no liquid damage etc. Check for foreign objects and possible shorts. Then check the power supply. It's easier with external types but some internal ones can be disconnected from the main board and tested individually. At the very least, check for shorts between the supply rails and ground. Also ...


3

/CMD files are a series of tagged records. Some record types have meaning only for certain features of some of the TRS-80 DOSes. Only two seem important for loading and executing them. byte: type byte: size* in bytes bytes[size]: data *size 0 → 256 bytes *size for type 1 only, size 1 → 257 bytes, size 2 → 258 bytes type 1: object code (...


3

The best resource is a book called TRS80 Disk and other mysteries. I found a copy online at: https://ia801709.us.archive.org/28/items/TRS-80_Disk_and_Other_Mysteries_1980_Harvard_C._Pennington/TRS-80_Disk_and_Other_Mysteries_1980_Harvard_C._Pennington_text.pdf My real copy is old and under a bunch of dust, but it does have the complete disk mapping ...


2

This is not a full answer, feel free to improve it. Let's start with the basics: Use ESD protection when touching any PCBs. Clean the PCBs.Inspect for any physical damages. Inspect all capacitors to see if any is leaking. Check any batteries. If possible, check the function of the power supply when it is not connected to any PCBs.


2

As a former floppy disc repair technician, you can indeed do this, but you risk damaging the read-write heads and/or the alignment of the heads, rendering the drive unusable until it is repaired or replaced.


1

After Googling this for an hour or two and not finding much, I have found something solid just minutes after posting my question! From page 40 of TRS8BIT volume 09 issue 02 from June 2015 there is an article on a "FreHD Expansion Interface" which includes this paragraph: If a WDC1771 Disc Controller is found then the LII ROM programs the chip to ...


1

I found one reference which exercises the floppy drives from the ROM-only BASIC, in just the ways I was looking for, the SAMS Photofact guide for the Model III. The simplest "script" it provides is the basic one which only makes a drive active as already found. The following Basic program will make Disk Drive 0 run continuously in the read mode. Change ...


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