I guess I've decided to do a board replication project starting on the
M100. At this point, I'm looking for a dead model on ebay but no one
wants to sell for less than $100 with shipping it seems. I'd pay $50 for
a 'for parts' unit.

Success will define this project if I can get some assistance. I have
designed pcb's in the past but for simple projects. This will be, by
far, my most complex effort to date. And I hope a success in this
project will lead to more restoration projects in the future.

Daniel

On Sunday, 5 February 2023 at 18:32:23 UTC-8, Daniel wrote:
> I guess I've decided to do a board replication project starting on the
> M100. At this point, I'm looking for a dead model on ebay but no one
> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
> a 'for parts' unit.
>
> Success will define this project if I can get some assistance. I have
> designed pcb's in the past but for simple projects. This will be, by
> far, my most complex effort to date. And I hope a success in this
> project will lead to more restoration projects in the future.
>
> Daniel
Are you planning on doing a drop-in replacement "replica" using modern components, or just an emulator? There's a copy of the service manual on Internet Archive that has the schematics, and should help get you started.
https://archive.org/details/TandyM100ServiceManual/page/n81/mode/2up

On 2/5/2023 9:32 PM, Daniel wrote:
> I guess I've decided to do a board replication project starting on the
> M100. At this point, I'm looking for a dead model on ebay but no one
> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
> a 'for parts' unit.
>

Welcome to eBay. I was recently looking for a Realistic (Tandy Brand)
shortwave radio. There were about 8 of them all listed as "not working/
as is/for parts". Prices ranged from $150 to around $300. The radio
only cost about $300 when it was brand new 40 years ago. Go figure.

bill

bill <bill.gunshannon@gmail.com> writes:

> On 2/5/2023 9:32 PM, Daniel wrote:
>> I guess I've decided to do a board replication project starting on the
>> M100. At this point, I'm looking for a dead model on ebay but no one
>> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
>> a 'for parts' unit.
>>
>
> Welcome to eBay. I was recently looking for a Realistic (Tandy Brand)
> shortwave radio. There were about 8 of them all listed as "not working/
> as is/for parts". Prices ranged from $150 to around $300. The radio
> only cost about $300 when it was brand new 40 years ago. Go figure.
>
> bill

> Welcome to eBay

I know, right?

Yeah the whole retro thing has become so big since covid that people are
expecting crazy money. I hate when people outbid and item, it sells,
then the same thing goes back on the market a day later. you know the
seller is looking for more money. Anyway that happened to me on a new
old stock sony walkman.

Black Epyon <Blackepyon01@yahoo.ca> writes:

> On Sunday, 5 February 2023 at 18:32:23 UTC-8, Daniel wrote:
>> I guess I've decided to do a board replication project starting on the
>> M100. At this point, I'm looking for a dead model on ebay but no one
>> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
>> a 'for parts' unit.
>>
>> Success will define this project if I can get some assistance. I have
>> designed pcb's in the past but for simple projects. This will be, by
>> far, my most complex effort to date. And I hope a success in this
>> project will lead to more restoration projects in the future.
>>
>> Daniel
> Are you planning on doing a drop-in replacement "replica" using modern
> components, or just an emulator? There's a copy of the service manual
> on Internet Archive that has the schematics, and should help get you
> started.
> https://archive.org/details/TandyM100ServiceManual/page/n81/mode/2up

I'm planning a replica, one-for-one drop in of the board and all traces,
stencils, etc. Some dead devices are due to battery leakage and traces
will be destroyed in many areas - but many components will be okay. In
these cases the device is usually salvaged for parts only and that means
one device removed from circulation. Like the commodore, I'd like a
board replacement and there's been very little interest in the project.

I have the service manuals already and also have Birt's modern remake of
the schematics from his github.

I need to get a dead device so I can depopulate the board, remove all
solder/flux, and do a high definition scan of both sides for all three
boards.

Later, I'd like to redesign the power supply and convert it to USB-C
input and rechargable batteries, but that's way down the road.

I plan on posting my progress of this project on this thread as I go -
barring health issues. Also, I invite community members interested in
helping with design and/or documentation.

Daniel

On Sunday, February 5, 2023 at 6:32:23 PM UTC-8, Daniel wrote:
> I guess I've decided to do a board replication project starting on the
> M100. At this point, I'm looking for a dead model on ebay but no one
> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
> a 'for parts' unit.
>
> Success will define this project if I can get some assistance. I have
> designed pcb's in the past but for simple projects. This will be, by
> far, my most complex effort to date. And I hope a success in this
> project will lead to more restoration projects in the future.
>
> Daniel

Hi,

Personally, for the limitations of the Model 100, I'd say go for a Model 1 board ...

As this is a replica, maybe add a VGA video OUT and USB keyboard IN and if possible a microSD card FDD or HDD to BOOT to OS and contain most if not all TRS-80 software and games.

..

On Tuesday, February 7, 2023 at 3:25:54 AM UTC-5, Daniel wrote:

> I'm planning a replica, one-for-one drop in of the board and all traces,
> stencils, etc. Some dead devices are due to battery leakage and traces
> will be destroyed in many areas - but many components will be okay. In
> these cases the device is usually salvaged for parts only and that means
> one device removed from circulation. Like the commodore, I'd like a
> board replacement and there's been very little interest in the project.

I have a couple of "parts boards" from dead 100s, but I specifically want the unique parts on them, so I would have to depopulate them before I send you the board (for which I have no use). I'm not sure how quickly you want to get these boards, but, given a bit of time, I could provide one.

> I need to get a dead device so I can depopulate the board, remove all
> solder/flux, and do a high definition scan of both sides for all three
> boards.
>
> Later, I'd like to redesign the power supply and convert it to USB-C
> input and rechargable batteries, but that's way down the road.

I would REALLY love to see that happen. There's lots of "improvements" that I think need to be made to these machines to make a modern replica board useful. Use modern RAMs instead of the Tandy modules. Maybe make the optrom socket JEDEC standard. Definitely the power supply, as you say.

-Josh

On 2/7/2023 3:20 AM, Daniel wrote:
> bill <bill.gunshannon@gmail.com> writes:
>
>> On 2/5/2023 9:32 PM, Daniel wrote:
>>> I guess I've decided to do a board replication project starting on the
>>> M100. At this point, I'm looking for a dead model on ebay but no one
>>> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
>>> a 'for parts' unit.
>>>
>>
>> Welcome to eBay. I was recently looking for a Realistic (Tandy Brand)
>> shortwave radio. There were about 8 of them all listed as "not working/
>> as is/for parts". Prices ranged from $150 to around $300. The radio
>> only cost about $300 when it was brand new 40 years ago. Go figure.
>>
>> bill
>
>> Welcome to eBay
>
> I know, right?
>
> Yeah the whole retro thing has become so big since covid that people are
> expecting crazy money. I hate when people outbid and item, it sells,
> then the same thing goes back on the market a day later. you know the
> seller is looking for more money. Anyway that happened to me on a new
> old stock sony walkman.
>

How about when someone says $200 OBO but then won't accept any offer
less than $199. Just had one of them, too.

bill

On Tuesday, February 7, 2023 at 7:16:07 AM UTC-8, josh....@gmail.com wrote:
> On Tuesday, February 7, 2023 at 3:25:54 AM UTC-5, Daniel wrote:
>
> > I'm planning a replica, one-for-one drop in of the board and all traces,
> > stencils, etc. Some dead devices are due to battery leakage and traces
> > will be destroyed in many areas - but many components will be okay. In
> > these cases the device is usually salvaged for parts only and that means
> > one device removed from circulation. Like the commodore, I'd like a
> > board replacement and there's been very little interest in the project.
> I have a couple of "parts boards" from dead 100s, but I specifically want the unique parts on them, so I would have to depopulate them before I send you the board (for which I have no use). I'm not sure how quickly you want to get these boards, but, given a bit of time, I could provide one.
> > I need to get a dead device so I can depopulate the board, remove all
> > solder/flux, and do a high definition scan of both sides for all three
> > boards.
> >
> > Later, I'd like to redesign the power supply and convert it to USB-C
> > input and rechargable batteries, but that's way down the road.
> I would REALLY love to see that happen. There's lots of "improvements" that I think need to be made to these machines to make a modern replica board useful. Use modern RAMs instead of the Tandy modules. Maybe make the optrom socket JEDEC standard. Definitely the power supply, as you say.
>
> -Josh

Hi,

The thing about the boards is if the board itself isn't totaled, the circuit shouldn't be too difficult to repair. Maybe just a bad cap or a chip died.

..

Josh Malone <josh.malone@gmail.com> writes:

> On Tuesday, February 7, 2023 at 3:25:54 AM UTC-5, Daniel wrote:
>
>> I'm planning a replica, one-for-one drop in of the board and all traces,
>> stencils, etc. Some dead devices are due to battery leakage and traces
>> will be destroyed in many areas - but many components will be okay. In
>> these cases the device is usually salvaged for parts only and that means
>> one device removed from circulation. Like the commodore, I'd like a
>> board replacement and there's been very little interest in the project.
>
> I have a couple of "parts boards" from dead 100s, but I specifically
> want the unique parts on them, so I would have to depopulate them
> before I send you the board (for which I have no use). I'm not sure
> how quickly you want to get these boards, but, given a bit of time, I
> could provide one.

That would be great. Yes I'd love them soon than later so I can get to work.

>> I need to get a dead device so I can depopulate the board, remove all
>> solder/flux, and do a high definition scan of both sides for all three
>> boards.
>>
>> Later, I'd like to redesign the power supply and convert it to USB-C
>> input and rechargable batteries, but that's way down the road.
>
> I would REALLY love to see that happen. There's lots of "improvements"
> that I think need to be made to these machines to make a modern
> replica board useful. Use modern RAMs instead of the Tandy
> modules. Maybe make the optrom socket JEDEC standard. Definitely the
> power supply, as you say.

This is where the community would need to come in. You're talking about
territory way outside my knowledge. The point of this project, for me,
is to allow for full restoration of these old devices without removing
them from circulation. Some say there are so many of them out there that
it's okay. Our community is far more niche than the commodore side of
things. If a board has extensive trace damage from leaking caps and
other issues, I'd love if a board could be replaced and the working
components populated on the new board. I know it's alot, but it's being
done all the time in other communities like the C64. Hell, you can order
a board of all revisions and a choice of colors. Some youtubers have
managed to make brand new c64's with off-the-shelf components and
homebrew replacement chips.

And creating boards that accept all the old components but modified with
improvements I'm totally open to - but it's secondary far in the future
unless the community jumps on the bandwagon.

Daniel

Daniel <me@sc1f1dan.com> writes:

> Daniel <me@sc1f1dan.com> writes:
>
>> I guess I've decided to do a board replication project starting on the
>> M100. At this point, I'm looking for a dead model on ebay but no one
>> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
>> a 'for parts' unit.
>>
>> Success will define this project if I can get some assistance. I have
>> designed pcb's in the past but for simple projects. This will be, by
>> far, my most complex effort to date. And I hope a success in this
>> project will lead to more restoration projects in the future.
>>
>> Daniel
>
> Project update: Solder sucker on order. I will continue my project once
> the thing is in my hands.

I'm well underway on depopulating the board. It's slow going. Needing to
melt new solder on the old, then using the solder vacuum to clean the
joint. Sometimes needing to do it two or three times to completely clean
it out. So far so good. The weather has been nasty here in California,
nasty for us at least. Many power outages and intense wind/rain
storms. Some tornado warnings north of us. Drought is more-or-less over
for most of the state finally.

I will continue with the desoldering job and get it as clean as
possible.

Then I'll move onto high quality scans of both sides before beginning
the replication.

I will dump everything on github so the community can assist, if
possible.

Daniel

I had no idea anyone was still interested in these. I just trashed a Model
100 a few days ago. A whopping 32k of storage, black vinyl case and power
supply.

It worked, but the screen would fade out after a few minutes. I had not
powered it on for around 10 years.

I can’t imagine using these for anything these days. But good luck with
your project.

Hi,

It's so sad to see somebody trash vintage computers when the chips can be so hard to find to repair another computer.

..

On Saturday, April 1, 2023 at 9:14:26 PM UTC-7, Bob Campbell wrote:
> I had no idea anyone was still interested in these. I just trashed a Model
> 100 a few days ago. A whopping 32k of storage, black vinyl case and power
> supply.
>
> It worked, but the screen would fade out after a few minutes. I had not
> powered it on for around 10 years.
>
> I can’t imagine using these for anything these days. But good luck with
> your project.

Walt Perko <r4rguy@gmail.com> wrote:
> Hi,
>
> It's so sad to see somebody trash vintage computers when the chips can be
> so hard to find to repair another computer.
>

Well, let’s not overdramatize. It’s just a crappy, 40 year old computer.
I’m not throwing away food in front of starving people. I’m not laughing
manically while lighting cigars off of a $100 bill in front of homeless
people.

Hi,

A lot of old chips are not manufactured anymore. We need to save them. It took me two years to find the last part to build a reproduction DAZZLER board. They quit making half the chips on that board back in the 1980s ... today I have the last chip that was in an obscure collections of chips.

The chips on all these old machines need to be recycled for repairing other old computers ... even Model 100s ... I have a working Model 100 ... I keep it under a plastic cover to keep dust out when I'm not playing with it. Yeah, it's not a great machine compared to my Altair 8800c or my IMSAI-JAIR or my IMSAI Z-1 or my Sol-20 that I'm slowly repairing and have to make my own cabinet for it as I only got lucky to get the main board and S-100 backplane. But all these machines use old out of date chips and they all have a lot of chips in common.

..

On Tuesday, April 4, 2023 at 8:52:35 PM UTC-7, Bob Campbell wrote:
> Walt Perko <r4r...@gmail.com> wrote:
> > Hi,
> >
> > It's so sad to see somebody trash vintage computers when the chips can be
> > so hard to find to repair another computer.
> >
> Well, let’s not overdramatize. It’s just a crappy, 40 year old computer.
> I’m not throwing away food in front of starving people. I’m not laughing
> manically while lighting cigars off of a $100 bill in front of homeless
> people.

On 4/5/2023 1:25 AM, Walt Perko wrote:
> Hi,
>
> A lot of old chips are not manufactured anymore. We need to save them. It took me two years to find the last part to build a reproduction DAZZLER board. They quit making half the chips on that board back in the 1980s ... today I have the last chip that was in an obscure collections of chips.
>
> The chips on all these old machines need to be recycled for repairing other old computers ... even Model 100s ... I have a working Model 100 ... I keep it under a plastic cover to keep dust out when I'm not playing with it. Yeah, it's not a great machine compared to my Altair 8800c or my IMSAI-JAIR or my IMSAI Z-1 or my Sol-20 that I'm slowly repairing and have to make my own cabinet for it as I only got lucky to get the main board and S-100 backplane. But all these machines use old out of date chips and they all have a lot of chips in common.
>
>

And yet, when people offer these old systems for sale they have no value
at all.

bill

Daniel <me@sc1f1dan.com> writes:

> Daniel <me@sc1f1dan.com> writes:
>
>> Daniel <me@sc1f1dan.com> writes:
>>
>>> I guess I've decided to do a board replication project starting on the
>>> M100. At this point, I'm looking for a dead model on ebay but no one
>>> wants to sell for less than $100 with shipping it seems. I'd pay $50 for
>>> a 'for parts' unit.
>>>
>>> Success will define this project if I can get some assistance. I have
>>> designed pcb's in the past but for simple projects. This will be, by
>>> far, my most complex effort to date. And I hope a success in this
>>> project will lead to more restoration projects in the future.
>>>
>>> Daniel
>>
>> Project update: Solder sucker on order. I will continue my project once
>> the thing is in my hands.
>
> Project update: Solder sucker received. Problem is massive atmospheric
> river with heavy rain, flooding, and high winds have made power
> intermittent. Waiting for power to be restored consistently before I get
> back on the ball.
>
> Daniel

Project update: It's been a tough six months. Health issues abound,
intense work schedule and family stuff has kept my hobbies in a rut. I'm
getting back into this replication project soon. Just wanted to keep
everyone updated.

Solder sucker is still in the closet in the box it came in. It didn't
even see the light of day so far. I hope the thing does the job I hope
it does.

Need to see if my soldering station is still on the spectrum.

D