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New to T models

CloudInMyHead

CloudInMyHead

Experienced Member
Joined
Aug 14, 2022
Messages
121
Location
Laguna Hills. California
I am new to the T models. I just picked up a NEC PC-8201A. I hope this is the correct place to post this as I know it's the sister model to the TRS-80 Model 100.
Here are some photos.

PXL_20231028_043745918.MP.jpg


Here is the memory. It's fully populated so I am guessing it is at it's maximum capacity. I dunno.
I'll read more of the NEC book today. Also, I'm not sure how to switch to the other ROM or if there is anything worth keeping on it. More reading necessary :)


PXL_20231028_041925617.MP.jpg


Looks like the battery has not leaked (yet) but I do want a replacement.
cleardot.gif


PXL_20231028_042747772.MP.jpg

I didn't see any CAPS looking bulging or discolored.
PXL_20231028_042805946.MP.jpg


PXL_20231028_042859110.MP.jpg
 
I'm looking for a REX# rom. I contacted Stephen Adolph and unfortunately, he's backordered with requests. So I don't have an eta. I also inquired about a Dial-a-ROM from another vendor and I haven't heard back yet.
I want both ROMS as then I can decide which I like better, something well done already or something I can customize :)
I also am looking for:
1. New internal battery
2. NEC case
3. An extra battery case
4. External PS for the NEC. I thinks it's more voltage than the Tandy


 
The dial a ROM is a good product, but it is not a substitute for the REX. it is definitely cheap enough though :D. Another product to consider is the Backpack drive. It uses an SD card as a disk drive, and as an added bonus you can put the card into a modern PC, add the files you want, and then put the card back into backpack to get the files onto your model t. I am fairly certain the backpack is available from the same vendor as the dial a ROM. I think the dial a rom comes in different flavors depending on which model you are going to be using it in, so make sure you specify it is for an NEC.

Have fun!

J White
 
Thanks J White.
I did look at the Backpack drive. I didn't see it say it would work on the NEC and when I saw special versions for non Tandy model listed but the NEC wasn't, I assumed they did not have a NEC version.
Any YES, I really want a REX#
 
Was trying to figure out how RAM I have and ran this T 100 code.

From the Club 100 support files (www.club100.org)...
HOW MUCH RAM DO YOU HAVE?
'''
?(256-PEEK(-1343))/4"K
The RAM capacity in Kbytes is reported on the screen. You'll get one of four
reports:
8 K
16 K
24 K
32 K
...

My Results:
36.25 K
 
Image that ROM! If you don’t have the equipment and/or don’t care about keeping an old insurance-adjuster ROM, I’d be happy to trade you your choice of Option ROM burned onto a chip.
 
I am currently loading TS-DOS from my Backpack drive onto my NEC 8201a. The PDF on their website (https://github.com/Jeff-Birt/Backpack/blob/main/BPD+ Files/Documentation/Backpack+ Manual V13.pdf) tells how to do this. I'd say it works with the NEC :D

Bootstrapping TS-DOS takes a bit of time, but ought to only be needed to be done if the memory is lost due to a cold start. Once you get a dial a rom or a REX, it will be on ROM.

I don't know if the software is any different on the dial a ROM, but the Model 100 version does not physically fit in the NEC ROM socket, so make sure you specify which one you need.
J White
 
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I wish there a write-up, of maybe not all, but some of the popular ROMS. I know the T-DOS is fairly popular I just don't know what the completion is, until I get a Dial-A-ROM or the coveted REX# ROM, which I plan on getting both. "J White", now you have me reconsidering the BackPack.
 
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I have a BackPack drive, and it is simply genius as an effective way to get files on and off a 'Model T'. I use it between a 100, 102 and 200, and use the microSD card from it with an adapter to get files from these systems onto my M1 MacBook and Windows 10 system, and back again.

On the 100 I bootstrapped TS-DOS from the BackPack, on the 102 I use a Rex#, and on the 200, I have a Dial-A-ROM. Bootstrapping uses up about 6.5K of available RAM, but is totally reliable in use, the Rex# is pretty versatile and uses no RAM, but also sometimes unloads itself from RAM, and can cause the 102 to crash - actually freeze up (very likely my 102, not the Rex#). The Dial-A-Rom I use just for TS-DOS and in use it's as solid as a rock (also uses no RAM).

The Rex# has the benefit of being able to load Option ROM images into it for use, and to save memory, so an effective backup for the system, but I think Steve is busy with other things so a Rex# might not be available quickly. The Dial-A-ROM doesn't have the means to backup memory from the computer, but does have a number of Option ROMs on board. It's also pretty inexpensive.

Personally, I find the combination of Dial-A-ROM and BackPack drive to be a very simple and effective way of putting my Tandy 200 to efficient use in combination with modern systems. The Rex# let me play with Option ROMs after I downloaded the images from the Club 100 site and that was really interesting - and why I have a Rex# in one machine and Dial-A-ROM in the other.

Incidentally, a replacement memory battery can be had from the same supplier as the BackPack and Dial-A-ROM - and undoubtedly others too.
 
Thanks AndyO,
That information was super helpful.

I've been in talks with everyone.
1. Steve for Rex# - Backordered and too busy at his real job at the moment, which I totally understand
2. Birt - Out of stock for Dial-A-ROM and the BackPack2
3. Gary Weber - He's going to burn me one of his ROMs and maybe an Ultimate 2 as well
I have to say - ALL THREE OF GUYS ARE SUPER NICE AND HELPFUL. As well as everyone I have met on this forum for all my vintage computers.
 
CloudInMyHead said:
I wish there a write-up, of maybe not all, but some of the popular ROMS. I know the T-DOS is fairly popular I just don't know what the completion is, until I get a Dial-A-ROM or the coveted REX# ROM, which I plan on getting both. "J White", now you have me reconsidering the BackPack.
Click to expand...
Duh.,
Gary Weber showed me the ROMs available page:
TANDY - NEC ROMS on www.web8201.net
 
I got the same response from Stephen when I asked about a Rex CPM for my 200 - it's a bit of a pity that such a great product for these old systems is difficult to obtain, but it's both a sign of how dependent we are on talented hobbyists for our ingenious solutions, and also how talented those hobbyists really are.

I think Jeff Birt tends to get stocks of products from his maker/friend fairly regularly, but I can understand why both the DAR and BackPack are out of stock. The first is probably the least expensive way to get TS-DOS without loosing RAM by bootstrapping it, and the BackPack is (I think) the only plug-and-play storage solution still available which doesn't depend on cabling to a host computer or the Telcom app.

For my use of these old systems, a means to move data created on them onto modern systems is crucial so I started using serial-USB cables before the BackPack appeared. But as that tells you, there are solutions using cables and software, and even TS-DOS (or an alternative) isn't strictly speaking necessary, because files can be up/down loaded via Telcom if needed - it's just so simple and reliable with the BackPack instead that the cost investment over a couple of years is quite negligible.

By the way, welcome to the world of the Model T. These machines may be rather basic by modern standards, but they are awesome examples of what simplicity can achieve.
 
OMG.
Twospruces said:
Regarding REX#, I built 25 units today for M100/T200. That's part of my backlog anyways.
Click to expand...
OMG Steve.,
Twenty-five units sounds like a substantial amount of work and time. I know everyone appreciates your dedication and effort you put into making and distributing the REX's. Your commitment to this, undoubtedly brings immense joy to those receiving the ROMs.

Steve. Your well-being and happiness are of utmost importance to us. We want you to continue supporting this hobby happily, rather than allowing it to become burdensome.

Your dedication is truly appreciated, and we value your commitment to making this project a success.

You are a Rock-Star in the community.
 
Twospruces said:
I built 25 units today for M100/T200.
Click to expand...
CloudInMyHead said:
Twenty-five units sounds like a substantial amount of work and time. I know everyone appreciates your dedication and effort you put into making and distributing the REX's. Your commitment to this, undoubtedly brings immense joy to those receiving the ROMs.
Click to expand...
Seconding this. REX# makes the M100 a whole different animal in terms of practical usability. Great work.
 
Appreciate the sentiments. I actually enjoy building, I just need to find time. Easier when the weather turns for sure. First snow today.
 
On the internal battery replacement, what is the best option?
1. Replace with new similar NiCad battery
2. Replace with button style battery so it's easier to replace
3. Replace with a super capacitor
And what are the benefits over any of them?
 
Based on the fact my 200 still has its original NiCad which measures out at 3.7 volts so has lasted pretty well, I'd say it's probably not necessary to think about eventually replacing a replacement - and besides, the 200 is so easy to dismantle. I'd go with a modern NiMh replacement for simplicity. These work well and fit in the same space, do exactly the same job, and cost around $5 apiece.

A supercapacitor is not likely to give you anything useful in terms of memory support other than for switching main batteries without RAM loss, whereas a NiMh is more likely to give you a month or so.

I've not looked at coin-cell type replacements since it looked like it might be a bit crowded on the board to fit one in place. It's also going to need fairly routine replacement, where the rechargeable can be fitted and forgotten for a few years at least.
 
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