PEB Help/Advise Please

[+arcadeshopper]

note.. this is in the pinned faq..save yourself a lot of time to check that first

[+Atari2600PAL]

7 minutes ago, arcadeshopper said:

note.. this is in the pinned faq..save yourself a lot of time to check that first

I’ve read the FAQs multiple times, including today, and couldn’t see the answer to this particular question. I’ll take another look thru thanks

[+Ksarul]

2 hours ago, Atari2600PAL said:

Many thanks, will give it a go then when it arrives 

Do note, that even though the drives will work, they work in single-density mode with a single density controller, so they won't be able to read or write to a floppy disk that has been formatted to double-density when connected to that single-density controller. That means that a double-sided disk will give you a formatted capacity of 180K (360 sectors on a TI) and a single-sided disk will give you 90K (180 sectors on a TI). You already noted that you expected the drives to work in SD mode, I just put this here to clarify for any future readers of the thread who hadn't performed the background check on how things work before they landed here. One-stop shops can be very useful.

[Duewester]

3 hours ago, Ksarul said:

Any of the double-density drives also work with single-density controllers, so your drives should work fine with the TI controller as long as controller, drives, and cables are all functional.

I've been slow to get the PEB I got on eBay inspected but the first thing I found when pulling the two drives out was bad ribbon cable. The wire (pin 40 I believe) right at the controller connection is worn though and the wire severed. I don't know if the box would work or not because I want to verify the box doesn't have these kind of problems before I even power it on.

The box has two bodged in sets of wires and I want to know what they're for.

 One is probably power and the other smaller set goes into the drive bay to some sort of capacitor/filter looking rig.

[+Ksarul]

3 hours ago, Duewester said:

I've been slow to get the PEB I got on eBay inspected but the first thing I found when pulling the two drives out was bad ribbon cable. The wire (pin 40 I believe) right at the controller connection is worn though and the wire severed. I don't know if the box would work or not because I want to verify the box doesn't have these kind of problems before I even power it on.

The box has two bodged in sets of wires and I want to know what they're for.

 One is probably power and the other smaller set goes into the drive bay to some sort of capacitor/filter looking rig.

The floppy cable is 34-pins, not 40. One the bodged wires, one probably is to add a connector/power to a second drive. A lot of folks made that mod (or added a splitter for the existing connector). Not sure about the filter-looking mod.

[Duewester]

On 7/2/2023 at 8:12 PM, Ksarul said:

The floppy cable is 34-pins, not 40. One the bodged wires, one probably is to add a connector/power to a second drive. A lot of folks made that mod (or added a splitter for the existing connector). Not sure about the filter-looking mod.

I didn't count pins just noted the damage was not on red stripe wire and assumed. My bad.

I'm still waiting on floppies from @arcadeshopper and looking for my old ribbon cables box. It's a work in progress.

[+Atari2600PAL]

Just received and tested the PHP1240 FDC and it seems to work fine. Will keep it as a spare and for my collection of original cards (not a bad find for $35 I hope) or I may get a 2nd PEB in the future when I have room for it.

 

(Would like to get a p-code card but not seen one on eBay since I got the PEB)

[+Atari2600PAL]

Have now fitted a working switch so I think that's all the PEB issues fixed now (just some new cards to fit when I have them)

 

Not sure it was worth all the effort and cost of fixing the switch, at least I'm not sure I'd do it again anyway. But it's nice that it works now.

 

(Thought I'd broken my floppy drives after putting it all back together, but I'd forgotten to turn on the TIPIPEB PI which for some reason causes hangs when accessing physical drives if PI switched off. I'm sure there must be an obvious reason though)

 

Many thanks for all the advise I've received, very much appreciated!

[+jedimatt42]

Most software does not access a specific drive. It accesses a named device. The system then visits the devices ( in order of CRU base address ), paging in their respective driver ROM that holds the Device Service Routine (DSR) associated to each device name. TIPI's ROM has a DSR associated to DSK1 (and the others ) so that it can handle mapping directories to the floppy device names. The mapping configuration is on the PI. When you access DSK1, the TI sends the request to the PI, and this blocks in a loop waiting for the PI to consume the message. If the PI responds with a 'not handled' message ( loosely speaking ) then the TIPI DSR returns to the visiting routine ( typically called DSRLNK ) which usually then continues visiting the next device. 

 

This facility was a stroke of genius by TI engineering. 

 

If you want to run the TIPI board but not have the PI operational, you can connect a switch to the top CRU base address jumper blocks. This would allow toggling the TIPI CRU base address high bit on or off, shifting it to well after the standard floppy disk controller when the ROMs are being visited. "TIPI.", "DSK0." and if using a TI disk controller, then TIPI's "DSK4." will still be accessible (if the PI is on) to most TI software. TI's floppy controller does not report 'not handled' to DSRLNK, so DSRLNK will not continue to search for the overlapping device name.

 

The floppy controller CRU base is 0x1100. The TIPI CRU base in your configuration should be 0x1000, and with the switch closed, 0x1800.

 

I think most 99ers never had a hardware configuration where they needed to know this forward thinking, powerful feature exists.

 

 

[+Atari2600PAL]

15 minutes ago, jedimatt42 said:

Most software does not access a specific drive. It accesses a named device. The system then visits the devices ( in order of CRU base address ), paging in their respective driver ROM that holds the Device Service Routine (DSR) associated to each device name. TIPI's ROM has a DSR associated to DSK1 (and the others ) so that it can handle mapping directories to the floppy device names. The mapping configuration is on the PI. When you access DSK1, the TI sends the request to the PI, and this blocks in a loop waiting for the PI to consume the message. If the PI responds with a 'not handled' message ( loosely speaking ) then the TIPI DSR returns to the visiting routine ( typically called DSRLNK ) which usually then continues visiting the next device. 

 

This facility was a stroke of genius by TI engineering. 

 

If you want to run the TIPI board but not have the PI operational, you can connect a switch to the top CRU base address jumper blocks. This would allow toggling the TIPI CRU base address high bit on or off, shifting it to well after the standard floppy disk controller when the ROMs are being visited. "TIPI.", "DSK0." and if using a TI disk controller, then TIPI's "DSK4." will still be accessible (if the PI is on) to most TI software. TI's floppy controller does not report 'not handled' to DSRLNK, so DSRLNK will not continue to search for the overlapping device name.

 

The floppy controller CRU base is 0x1100. The TIPI CRU base in your configuration should be 0x1000, and with the switch closed, 0x1800.

 

I think most 99ers never had a hardware configuration where they needed to know this forward thinking, powerful feature exists.

 

 

Many thanks for the detailed information @jedimatt42, very informative thanks

 

The reason I don't always turn the PI on is that currently I'm just playing/testing with the system, rather than using properly, and so am worried I might forget to turn off the PI before cutting power and corrupt something (not really a big deal if I did though). But I'll keep it "as is" as in the future I'll probably just leave it on anyway.

 

I've not programmed anything since I had to give up work in 2018, so am building my system ready for the time when I can start using it in earnest

 

Thanks again

 

 

[+Atari2600PAL]

On 7/10/2023 at 1:35 PM, Atari2600PAL said:

Just received and tested the PHP1240 FDC and it seems to work fine. Will keep it as a spare and for my collection of original cards (not a bad find for $35 I hope) or I may get a 2nd PEB in the future when I have room for it.

 

(Would like to get a p-code card but not seen one on eBay since I got the PEB)

Just purchased a P-code Card, I think my PEB is full now (if it works, won't know until it arrives in a few weeks)

 

Slot 8 is reserved for the stupidly long floppy cable!

 

Am wondering if I could buy an FD controller end plug to fit further down the cable and (after testing) cut off the excess ribbon?

 

Are the plugs available please? If so, what should I be searching for please?

EDIT: I cant just use a shorter cable as its modified at the FD drives ends to make the drives 40 rather than 80 track

 

Many thanks

[+Atari2600PAL]

8 hours ago, Atari2600PAL said:

Are the plugs available please? If so, what should I be searching for please?

Have sussed out what they are called and have a few on order, thanks

[Stuart]

31 minutes ago, Atari2600PAL said:

Have sussed out what they are called and have a few on order, thanks

An IDC connector is hopefully what you've found. A small cheap vice off eBay provides a good way of fitting the connector to the ribbon cable in a controlled fashion. 

[+Atari2600PAL]

10 minutes ago, Stuart said:

An IDC connector is hopefully what you've found. A small cheap vice off eBay provides a good way of fitting the connector to the ribbon cable in a controlled fashion. 

Yes, that’s what I found thanks

 

Will practice on a spare ribbon first

[+OLD CS1]

9 minutes ago, Atari2600PAL said:

Will practice on a spare ribbon first

Good approach.  As I tell my interns and mentees: "measure once, cut twice!"

[+arcadeshopper]

I sell new cables of various lengths and setups.. and dual drive kits for pbox 

[+Atari2600PAL]

Just now, arcadeshopper said:

I sell new cables of various lengths and setups.. and dual drive kits for pbox 

I have a short cable that came with the PEB, but the long cable has extra wires running from the plugs at the drive ends that are part of the circuit that makes the 2 off 80 track drives I have work as 40 track. It’s a bit of a spaghetti tbh as there’s also a small circuit board squeezed in behind the drives. I have one of your mounting brackets holding it altogether though.

 

Am going to use my old cc9900 to test the cable modification so I don’t damage the MG modded one (that is working a treat btw, thanks)

[+Atari2600PAL]

23 hours ago, Stuart said:

A small cheap vice off eBay provides a good way of fitting the connector to the ribbon cable in a controlled fashion

Just tried with a pair of pliers on a spare ribbon and bent the pins (was worth a try I thought, wrongly). Tried again in a big vice in the garage and that seems to of worked ok

 

So have ordered a mini vice for doing the real thing, should arrive tomorrow, as I can't detach the cable from the circuit board and drives and don't want to cart them all out to the garage. The small vice will let me do it with the drives staying in the PEB

 

Many thanks for the advise @Stuart

[+Atari2600PAL]

All done and working, many thanks for the advise/tips

 

Nearly cut the cable too short and then nearly fitted the plug the wrong way around, but I caught myself each time!

[+Atari2600PAL]

I was wondering which 3.5” floppy drives are suitable for use with the CC9900 FDC

 

I was thinking about getting a couple of Samsung SFD-321B/LEC, but not sure if they are compatible to use as DSK3/DSK4  external to the PEB

 

I’ve kind of ruled out a Gotek as I only have an M1 Mac and therefore no windows machine for the various tools. And I do prefer old school

 

I was wondering if anyone has any thoughts please?

 

Many thanks 

[+arcadeshopper]

48 minutes ago, Atari2600PAL said:

I was wondering which 3.5” floppy drives are suitable for use with the CC9900 FDC

 

I was thinking about getting a couple of Samsung SFD-321B/LEC, but not sure if they are compatible to use as DSK3/DSK4  external to the PEB

 

I’ve kind of ruled out a Gotek as I only have an M1 Mac and therefore no windows machine for the various tools. And I do prefer old school

 

I was wondering if anyone has any thoughts please?

 

Many thanks 

all 3.5" drives are either hard wired to DSK2. or are jumperable 1 or 2.. you can use a special hand made cable or switch838's switchbox to set the drive number manually on the cable. 

you can use either a 800k or 1.44 drive in 800k mode but you will only get 40 track/dsdd off either of them..  if you are using HD disks on the 1.44 cover the hd hole with opaque tape so it switches to DS/DD mode..  these are both 80 track drives 

flashfloppy flashed gotek just uses dsk files on a fat32 disk, should be just as easy as a pc on a mac I have preflashed modded goteks in stock if you need one or all the info is at flashfloppy's github https://github.com/keirf/flashfloppy

 

 

[+Atari2600PAL]

15 minutes ago, arcadeshopper said:

all 3.5" drives are either hard wired to DSK2. or are jumperable 1 or 2.. you can use a special hand made cable or switch838's switchbox to set the drive number manually on the cable. 

you can use either a 800k or 1.44 drive in 800k mode but you will only get 40 track/dsdd off either of them..  if you are using HD disks on the 1.44 cover the hd hole with opaque tape so it switches to DS/DD mode..  these are both 80 track drives 

flashfloppy flashed gotek just uses dsk files on a fat32 disk, should be just as easy as a pc on a mac I have preflashed modded goteks in stock if you need one or all the info is at flashfloppy's github https://github.com/keirf/flashfloppy

 

 

Many thanks for the info

 

I’ll have to have a think about which path to go down

[+Ksarul]

One note on 3.5 drives, early 3.5 drives were actually available as 40-track DSDD drives for a short while (I have a pair of EPSON drives like that). The early 80-track DSDD 3.5 drives often had a set of jumper blocks to allow you to set the drive between drives 1 and 4. Later, all drives were just hardwired as drive 2 (some still had the pads on the layout for 1-4, but that feature disappeared over time).

 

One other note on 80-track drives connected to a controller set for 40 tracks: it generally doesn't double-step the tracks, and so the formatted portion of the disk is limited to the first 40 tracks on each side (a potential compatibility issue if you are trying to exchange disks).

[+Atari2600PAL]

6 hours ago, Ksarul said:

One note on 3.5 drives, early 3.5 drives were actually available as 40-track DSDD drives for a short while (I have a pair of EPSON drives like that). The early 80-track DSDD 3.5 drives often had a set of jumper blocks to allow you to set the drive between drives 1 and 4. Later, all drives were just hardwired as drive 2 (some still had the pads on the layout for 1-4, but that feature disappeared over time).

 

One other note on 80-track drives connected to a controller set for 40 tracks: it generally doesn't double-step the tracks, and so the formatted portion of the disk is limited to the first 40 tracks on each side (a potential compatibility issue if you are trying to exchange disks).

Thanks, the double stepping / incompatibility concerns me the most

 

The idea came about because I have the powered external case that I got my 5 1/4" drives from to put in the PEB (along with the stepping board) and I thought I could make use of it in a cheap project rather than it just going to landfill

 

I can pick up 2 unused 3 1/2" drives, 5.25 to 3.5 adapter trays and power adapters for about £50 all in, which I didn't mind forking out for given I didn't know how much I might even use them (if I were to get a couple of shift838 adapters that would effectively double the cost of the project)

 

I don't really see me needing a gotek as I have the TIPI. As I say, this is more about making use of something that will otherwise go to scrap and because I like old school

 

But the incompatibility that a lack of double stepping could cause means I think I'll hit the idea on the head and bin the case

 

Many thanks

 

 

[+jedimatt42]

7 hours ago, Atari2600PAL said:

...

 

But the incompatibility that a lack of double stepping could cause means I think I'll hit the idea on the head and bin the case

 

...

 

 

It only creates an incompatibility with other people or yourself if you switch to an 80 track controller. So you have to ask yourself if that is an actual use case you have...