Bill, I saved almost all of my CP/M stuff in files in my master "everything I've ever done" hard drive archive, so if there's anything you need (WordStar in file form, rather than disks), let me know.

I found a copy of Adventure (Colossal Cave) for CP/M, and copied that all into User space 1.? That's always good for a ten-minute break, too...
~~

Mark Moulding

Alison, I picked up a few weeks ago.? It went together in about an hour, and is very close to what you described.? It uses a Z-180 (Z*) code compatible, plus two serial ports (and some other stuff) on-chip.? It comes with a micro-SD pre-loaded with several versions of CP/M and a few others as well (Z-System, Forth, Basic).? Each "Hard drive" on the SD card is broken into 16 "Slices", each of which is the 8 MB maximum size for CP/M.? The whole thing is only a little bigger than a deck of cards, and costs about $75.? Looking at the listing on Tindie, it appears that it may not be available much longer...

It's really fun to use - I leave it plugged into my main computer (it can be powered from the USB-serial adapter).? Then when I'm working on something else and need a break, I just fire up my H-19 emulator, and away I go!? I've loaded WordStar (my favorite editor of that era), as well as Turbo Pascal (which achieved for me what P-System did for you), so I'm back in 1981.
~~

Mark Moulding

>>>Early on, CP/M computers with primiive software and floppy disks really slowed software development. But that's all I had; I didn't know any better. It sure as heck beat a CPU manufacturer's development system with paper tape and a teletype! So I was in heaven. :-)<<<

I hear an Amen!? ?

For any system running off TTY and slow storge and minimal tools was a serious
handicap.

PRE CP/M development with SYS-8 (or the PT equivilent) was slow and awkward.
Same for any of the other CPUs.? The 1802 has the potential but most systems are?
low end so paper tape (cassette tape) wis about it and the tools are weak too.? I can?
say the exact same for 6800, 6502, Signetics 2650,8085, Ti9900, PDP-8, and many?
others.

FYI I believe the first break though was UCSD Pascal Psystem, in my case on
Northstar Horizon.? IT got me several things a language faster than interpreted
BASIC and better structured, a real IDE with a solid P-compiler and a real
screen editor.? In 1979 that was a big deal!? ?CP/M I'd been running since V1.3
and all of the neet stuff had to be transferred from 8"SSSD to NS* hard sector
5.25. With S100 it was easy to add a fairly low cost controller card and scrounge
up an 8" SC800 (loud and heavy) as a added disk and transfer media.? ?After that
C compilers started to appear (BDS-C was one of the good ones) and decent
configurable full screen editors like Vedit and programming became faster
and more efficient.

After 1977 (late in the year) I'd switched ot glass terminal and next year a real
printer (anadex DP800).? When CP/M that was a solid development platform and?
was mostly turnkey (no toggling in a boot).? From then to early 1980 I move from?
CPM V1.3, 1,4 then 2.2 and added third party tools.? The scheme was the box?
with a power switch and maybe reset and mass storage.? Front panel was passe.

AS to CP/M 86 on new hardware... that would be a task and a half.? IT was written
in base 8086 and did run well on any 8086/88 based XT class box.? It would morph
to CCPM.? DRI also had a version for Z8000 and its written in C (K&R dialect) and
that would be easier to port to newer or non x86 hardware.

For those really into it... go here???
also see?

My idea of a compact Z80 system would be 4mhz or faster (10mhz parts are easy to find)
64K ram mappable (and boot) 256K eprom (boot, system, base utilities (small romdisk) and
a larger mass storage such as uSD 1gb is far more than needed.? two serial port such as
Z80 dart).

Allison

ajparent1/kb1gmx wrote:

There are two forms of CP/M experience:
Small, slow and cramped typical of early floppies of 120 and 241K size.
High performance using fast large media (hard disks, IDE, CF, SD). [snip]

That's a good summary of CP/M usage, Allison. It mirrors my experience as well.

Early on, CP/M computers with primiive software and floppy disks really slowed software development. But that's all I had; I didn't know any better. It sure as heck beat a CPU manufacturer's development system with paper tape and a teletype! So I was in heaven. :-)

As better CP/M editors, debuggers, assemblers, and compilers were developed, it became much easier to develop code. Things like the SLR180 assembler and Turbo Pascal were great productivity tools.

Then hard drives and higher CPU clock speeds were added, and the computer's speed no longer limited your productivity; the only limit was YOUR speed and creativity!

For me personally, the PC was a setback. It put me back at the bottom of the learning ladder. It was much slower than my Z80 system (a Heath H89 at the time), and its byzantine architecture made it much harder to use. I tried, but by the late 1980's I gave up. PCs basically became an appliance; a platform to run someone else's hardware and software. My time and talents went into other hobbies (electric cars), and in continuing to develop new applications for 8-bit microcomputers professionally; areas where I felt I could still accomplish something.

After I retired, I felt a need to get back to when computers were FUN. Something a beginner could learn and understand, and build and create useful things themselves. It givee me a sense of accomplishment you can't get by buying everything and running someone else's software.

My hope for the Z80MC is to get it to the point where *it* can be a good platform for developing vintage hardware and software. Done right, it's going to be easier to use it than try to do it on a PC! You can be running your CP/M programs even before the PC finishes booting. :-)

Thus, I'm hunting around for a video/terminal application. That's the obvious missing link.

Lee Hart

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

ajparent1/kb1gmx wrote:

old analog monitors were pushing hard at 80 chars but crisp at 64...
at 64 chars most editors and apps were easy to live with, but less
tended to really suck...

I agree with your reminiscing, Allison. I have an Atari 800 with 32-char screen; its NTSC video is fuzzy and painful to read. I had an Osborne O1, and its 5" 50-char CRT was also poor. I had an S-100 64-char video card with 12" Ball monitor that was very readable. The Kaypro/4 9" 80-char CRT was decent, and my Heath H19/H89 12" 80-char CRT is probably the best of my antiques.

Modern LCD monitors are highly variable. Many have poor color NTSC conversion, with lots of artifacts and aliasing. But more expensive large-screen LCDs can be pretty good; they just get overly bulky (a 17" LCD is overkill for CP/M use).

before the CTRC part it was mostly TTL and a lot of parts.

Yes; brute force circuits. But by 1978-80, Lancaster, Wozniak, Sinclair etc. were showing us video circuits that used finesse and cleverness instead of brute force. That's the philosophy I'm after. How to produce good video without lots of parts or rare/expensive chips.

Graphics adds even more... not much graphics in Z80 CP/M applications.

Right. But today, people kind of expect/demand graphics. Most early systems that had graphics used "character" graphics; a special character set with graphicsh symbols. If my board can do this, it can emulate the screens of a TRS-80, Kaypro, Heath, VT-100, etc.

Since RAM is now cheap and it saves a character generator chip, I can make it a graphics display and "draw" the characters with the Z80, like the Mac did. I picked a 384x192 pixel screen for my Z80-VID design because it allows a 6x8 font to produce a 64-character by 24-line display, or even 80 x 24 with a proportional or ugly 4x8 font. This gives it a programmable font, to better emulate vintage computers, without "pushing" the NTSC bandwidth too far.

But... is all this reasonable? Would anyone build or use it? Or does it produce a display that nobody likes?

USB is easier to get PS2 is starting to get scarce.

Yep. But there are USB-to-PS2 adapters. That provides a path for the guy that wants to use his old USB keyboard.

Lee

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

On Wed, Jul 29, 2020 at 11:22 AM, Lee Hart wrote:

I'm not sure how much resolution is "enough". 32, 40, 64, and 80 chars/line were all common. For a small screen, are the lower resolutions OK? The quality of TVs, monitors, and LCDs can limit the bandwidth as much as the video board.

Lee,

The old analog monitors were pushing hard at 80 chars but tended to be crisp at 64.
The trade is that at 64 chars most editors and apps were easy to live with but less
(Osborne at 50chars) it tended to really suck for a lot of aps and editors or program
development.

The Kaypro used decent monitor (Ball and friends) and at 80
chars looks very good.

The bigger issues is before the CTRC part it was mostly TTL and a lot of parts.
(scan, row and dot counters), plus rom for the character generators.? Graphics
adds even more.? Generally not much in the way of graphics in Z80 CP/M
applications.? Things important were the full set of attributes and cursor
controls.

The IBMPC was pretty much in step with what video was at that time it was
MDA to CGA that improved that and morphed into VGA and on. Two things
had to happen one was monitors especially color had to go up in resolution
and down in price.? Also memory had to become cheap.? The PC with graphics
was late 80 or later depending on the budget!? That was pushed by apple
as IBMPC didn't have a graphic GUI until windows 3 (yes there was 1 and 2
but they stank up the place).? I still have a? 1998 S7 video cards that did
640x480x8 colors the VGA standard.

One problem I've found with LCDs is the NTSC inputs are very picky as to timing or
the screen will be offset or have the wiggles and they want NTSC color timing!

Finding a RCA or sanyo/panasonic analog monitor is tough!? I have a ball I've
kept for some project as they are scarce and it takes three input Vsync, Hsync,
and Video and by jumper option any combined flavor of that up to NTSC mono.

One set of systems I have is the Visual 1050 system Z80 main cpu and 6502 for the?
video that does both bit graphics (320x240 mono) and character modes.? At the
time it was done that was 16K of Dram for the bitmap (about 2k for characters).

Again USB is easier to get PS2 is starting to get scarce.??

Over all computer video as we know it is a recent thing being less than
2 maybe stretching it 3 decades old.? ?Before that I was using a 21 inch
Trinitron and VAX/VMS DECwindows at 1024x1024 color on a
MIcroVAX-II/GPX.? That was the tail end of the 80s when the worstation
era? [1megapixel, 1MIPS]?and desktop or deskside was the ne plus ultra.

ajparent1/kb1gmx wrote:

Not a fan of TMS9918, hard to get too.
As I have a large collection of CP/M base systems...
S100 several... (Altair, NorthStar, Compupro)
AmproLB+
Kaypro 2 and also 4/84
DEC VT180 (z80 board + Vt100)
Osborne portable
Epson PS-8...

A good summary, Allison. I too have a pile of vintage systems to look at, plus I've stared at the schematics of lots more. Learn from the experts! :-)

One common thread is that most of the designers were either in tearing hurry, or trying hard to do it on the cheap. When they were in a hurry, we got conservative designs with lots of parts, but poorly optimized (early IBM PC video). When they wanted cheap, we got minimalist hardware that barely worked with serious performance compromises (Sinclair ZX80).

I think there is a third approach in-between these two extremes. You can do more with less, if you have time to be thorough and a high degree of skill. The Apple II and early Macintosh computers were examples of this. Not much hardware; but it did a lot; and without the performance compromises (like the video monopolizing the CPU's time).

NTSC, Try to find a monitor.

I'm aiming for systems that can do NTSC or PAL. If you don't have an old TV or CRT monitor, there are lots of little LCD TVs with NTSC or PAL inputs.

S100 and friends use either 64Char x 16line (processor tech VDM-1) and
similar. Later ones use 80x24/25 (just more parts).

I'm not sure how much resolution is "enough". 32, 40, 64, and 80 chars/line were all common. For a small screen, are the lower resolutions OK? The quality of TVs, monitors, and LCDs can limit the bandwidth as much as the video board.

I happen to like a programmed atmega or two (Grant Searle) as it allows for
VGA, PS2 keyboard.

Lots of people do. It's a common approach, and "fashionable" today, especially if you're using it with a modern micro.

The above also reflects that if you do video you need a keyboard.
Most common keyboards are now USB.

Yes, that is the case. Most people don't want to make a keyboard; they would rather use something they already have. Maybe an old PS2 keyboard, or more likely it's USB.

But the whole point of hacking around old computers is that you should be able to interface whatever you like! Not limit yourself to just what the developer had in mind.

PS2 is hackable; just about any micro can interface it. USB is much harder; you pretty much need a modern micro to talk to it.

Lee Hart

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

There are two forms of CP/M experience:
? Small, slow and cramped typical of early floppies of 120 and 241K size.
? High performance using fast large media (hard disks, IDE, CF, SD).

The bulk of CP/M systems I've done are:
Z80
64K ram with eprom overlay for boot, system load, hidden bios,? and utility (256K).
IO as needed to get to the world, dual serial is usual? (SIO or DART, or 8251A)
Maybe a PIO or 8255 PPI
A few include either a timer (8253, or similar) or periodic interrupt.
? Time keeping is not required by CP/M but is useful for applications.
Mass storage
? Over time that was floppy,?
? IDE hard disk? (its not that hard especially if you skip the high byte)?
? Later CF? (does 8bit memory mode nicely still can be found often faer bigger than needed)
? and finally SD? (programming for it is a PITA).

Other storage can be EEprom really slow write but fine for read more
than write and Eprom (read only media) or large RAM (Ram disks).
These can be be ports or part of the main address and mapped in
and out.? Ports using 8255 PPI or LS273 are easier, adding a small
counter (7 bits) can make it easier still.

CP/M wants based on experience larger disks in the 1M to 8MB range.
IF the disk used is larger you partition it in the BIOS (there are other ways)
But a hint do not do all 16 possible devices as you are wasting ram 4 logical
drives is a good working number.? NOTE: CP/M 2 can only address a logical
drive of 128x65536 or 8MB (internal math limit).? Any of the CP/M replacements
P2DOS and later can take that to 1GB however with a flat directory stay at 8mb
and partition for 4 working drives.

Serial or simulated serial IO makes it easier for supporting ported apps to
a system.? Memory mapped video adds parts as it hen has to be mapped
in and out and applications need to stick to standard interfaces and that
can complicate software design.? Its easier if the IO looks like the nominal
console of the day terminal (ADM-3 or VT52, Vt100, H19) or something
that has the feel of TTY (yech!).

FYI if you have larger storage you can remap any drives partition.? Hint?leave
the boot drive as boot drive.? CPM can handle any format but for modern
non floppy that means translating to LBA and then doing sector deblocking
as CP/M assumes 128bytes as logical sector and most modern media is 512.
For that I use 16384 tracks and 4 logical sectors per track (for an 8mb "disk").
That helps with the deblocking code and the "track" is then the LBA address
(Plus any offset for partitioning).? CP/M BIOS math is rather archaine in its
explanation for the disk parameter tables.

As a convenience the system can be loaded from Eprom.? I do that all the time
as it makes the system less dependant on getting it initially on media.? The latter
can be a pain with current system with no support or difficult for that.? CP/M
does not care how it gets in ram (its the job of the bios!).? Even loaded from Eprom
its easy to allow for soft loading from disk as a file.

There is enough free and useful software to fill a large disk!? I have about 18mb
of software I use on the AmproLB+(45MB)? and NS Horizon (32mb) hard disks.

Allison

Not a fan of TMS9918, hard to get too.

As I have a large collection of CP/M base systems...
S100 several... (Altair, NorthStar, Compupro)
AmproLB+
Kaypro 2 and also 4/84
DEC VT180 (z80 board + Vt100)
Osborne portable
Epson PS-8

If one wants to copy classic S100 with front panel do the imsai it was better.
However that died rather fast leaning toward FLoppy based turnkey systems.

Most systems with video or character displays went three ways:
Sinclair ZX80 used the cpu to do it (cheap video), high cpu consumption and only
NTSC, Try to find a monitor.? Also if its small (MC in mint tin) the average 9"
monitor dwarfs it.? Most video systems had upper//lower case.

S100 and friends use either 64Char x 16line (processor tech VDM-1) and similar.
Later ones use 80x24/25? (just more parts).
TRS80 was of the VDM-1 style of 64x16 All upper for base system and later
versions added lower and 80 char.

Epson PS-8 was a 80x8 LCD with 6803 support for the display and random stuff.
Tandy trs80 M100/Koyocera,NEC8200 were all 40char wide by 8 line LCD.

Later ones use SMC5027 or 6545 CTRC chips with all the surrounding glue and
speed parts.

I happen to like a programmed atmega or two (Grant Searle) as it allows for
VGA, PS2 keyboard.

nearly all of the above had chip counts that were not small format friendly.
The most compact and complete is the ELF VT-102? but that needs the
1802 for half the task (ram and DMA refresh).? It also needs atmega for
the PS-2 keyboard.

The above also reflects that if you do video you need a keyboard.
Most common keyboards are now USB.

The alternate path is a 320x240 LCD with a 40 x 20 screen, still need
MPU to make that go.

Allison

Richard Cini wrote:

I do like the VID design, but here are a few things I thought of:

If you don’t have an aversion to using a PLD, a small GAL like a 16V8
might be useful for decoding and would still be period-appropriate.
There are several “new” designs in both the Retrobrew S100 and ECB
designs that use them, and they’re still available online from secondary
suppliers or eBay.

I've used PLDs in other designs for clients. They certainly reduce the parts count, and are good for "get it out the door quick" projects. They're great for commercial products that must fit in a certain size, and to keep your design safe(r) from copycats.

But they don't have the longevity of generic widely-sourced parts. I still have a pile of disk controller boards I can't build because the parts are no longer available.

PLDs also seem less suitable for hobby projects when you *want* people to be able to duplicate it. There are problems finding parts, finding programmers, and writing the equations to program them. They feel like a closed-box solution.

For the RAM, if you don’t need 128k, I might consider something like a
Cypress 32kx8 which is in a 0.300” DIP28 (rather than the normal
0.600”). That saves some space.

Yes, I use them on several of my kits. Once they got used by the millions in early PCs, they became generic. Lots of sources, and still available new.

They enabled another trick: If you look at my 6502 Badge and VIP2K kits, you'll see the 32k 0.3" RAM that hides *under* the 32k 0.6" EPROM. Their pinouts are almost the same, so it's easy to wire up, too.

The reason for the 128K RAM on the Z80-VID was to try to make a CP/M system on two boards. One is the existing CPU board, with Z80, 32K RAM, 32K EPROM, and 8-bit I/O ports. The second is the VID board, with NTSC/PAL video, SPI to run an SD-card for "disk storage", and more RAM so there's enough for 64K for the Z80, plus 20K for the video screen.

Alas, there are still too many parts to fit on a 3.5"x2" card without PALs, surface mount, modern parts, etc. But hope dies hard; maybe there's a way...

Lee Hart
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

开云体育

Actually, I'm already doing a re-spin of the product, to make it more environmentally robust, use a better A-D converter (the one I'm using now has caused many problems), and fully isolate an RS-485 interface.? I'll still need to produce a limited number of my existing design, in order to support spares for existing installations, but in the future I'll "mass"-produce only the newer version.

So, although it wasn't my original intention, I'll see what I can do about changing to a more off-the-shelf display.? A quick perusal of DigiKey doesn't turn up *any* 7- or 8-digit displays, and the 4-digit ones start at about twice the size (and twice the price, and I'd need two), but I'll keep looking.

In the meantime, if a smaller quantity would help out, I'm sure I can spare a few (or a few dozen, probably - I'll check my stock the next time i get to my warehouse). Contact me off-list and we can work out the details.
~~

Mark Moulding

Actually, I'm already using the MAX7219, because it does save so much work and there are easily-available libraries to drive it.? The reason I liked the display I'm using is that it's the right size (about 1-1/2" / 35mm wide), and has some separate indicator LEDs built in.? If they do run out, I'll just plant some smaller 4-digit displays directly on the board, along with some separate indicators.? This is all inside a chassis anyway, used for setup, configuration, and calibration, so it doesn't need to meet up with a fancy front panel.

One of the advantages of providing niche products is that they're not particularly sensitive to component pricing; most of the unit price goes to amortize the original engineering.? In most cases, there simply isn't a competitive product available, and other ways of accomplishing the customer's job are far more expensive, so everybody wins.

Thanks for the pointer to this display, though - having a couple of these around for quick knock-together projects could be pretty handy!
~~

Mark Moulding

Mark Moulding wrote:

Lee, I probably caused the availability problem with the original
display you were using. I found that to be a really neat display, so I
designed it into a specialized low-volume product I produce for a
client, and to ensure enough stock, I bought all they had (about 1,100
of them).

Hi Mark,

Aha! So THAT's where they all went! When we designed the badge, I ordered a couple hundred for the VCFMW show and follow-on orders. These were quickly gone; but when I tried to order more, MPJA said they were all sold. That was the "end" of the 6502 badges.

Luckily, I still had a couple boxes set aside for the Z80MC. Otherwise, I would have been out of business on it as well.

Then last year, one of the VCFMW guys (Mike Lee) found some more on ebay. So we were able to make another batch of badges for the show. I still have ~30 left, so the 6502 badges are currently available again. (Just don't buy 'em all).

Lee Hart

--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

smmccown@... wrote:

Do you have a datasheet or part number for the replacement LED display?
I would like to read about it.

I bought them on ebay. No data sheet or manufacturer's name. It's marked 72R02PHIL, date code T9718.

Lee Hart
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com