21 résultats trouvés

par engelen
11 mars 2024 22:15
Forum : Tous les Pockets
Sujet : Mystery TRS-80 PC-1 variant of the Sharp PC-1211
Réponses : 1
Vues : 85

Mystery TRS-80 PC-1 variant of the Sharp PC-1211

Hi,

I have two TRS-80 PC-1 pocket computers and a Sharp PC-1211 which are all the same, or are they?

I noticed that one of my TRS-80 PC-1 is different, because the lower PCB tucked below the top PCB is different and looks similar to the PC-1210 (which has less memory). In the picture, the top TRS-80 is the same as my PC-1211 and the lower PCB is recognizable by the two round test pads right below the battery compartment. The bottom picture is the other TRS-80. It has no test pads, extra diodes, extra wires: a long black jump wire and yellow/blue wires where the blue is not even connected anywhere. Looking carefully at the solder job, it seems done in the factory and not modified by someone.

Image

The yellow/blue wires in the bottom pictured TRS-80 are also visible in the PC-1211 pictured on the Vintage Calculators site http://www.vintagecalculators.com/html/ ... 0_pc1.html except that in my case the blue wire is not connected at all and there is also a black wire. Also the back case does not have the copper screws but regular screws. The bottom PCB without the two test pads and with the extra diodes looks the same as the PC-1210 also shown on the vintage Calculators web page.

Perhaps this "mystery" TRS-80 machine is an early version or prototype? It has the annoying problem that it crashes randomly after a while and loses its memory. Because the machine is not stable, I won't install a new LCD in that machine and I may decide to junk it.

Has anyone noticed these differences before?

What variations of these TRS-80 PC-1 / Sharp PC-1211 exist? Are some of these versions unstable?

- Rob
par engelen
21 mai 2023 02:18
Forum : Tous les Pockets
Sujet : Sharp PC-G850 assembly experience
Réponses : 2
Vues : 1366

Re: Sharp PC-G850 assembly experience

I have no complaints about the assembler and monitor of the PC-G850VS. The monitor shows the correct register values, but does not show the auxiliary registers.

Perhaps you have an interrupt routine activated that alters registers before display?

Registers are displayed with monitor break points. There is also a ROM routine that displays registers: CALL 0xbd03

PS. I wrote Forth850 in Z80 assembly from scratch using the as80 assembler. Writing assembly routines for Forth850 is relatively easy with the built-in assembler to define Forth words in Z80 code. See the examples on how that works.

- Robert
par engelen
06 avr. 2023 20:17
Forum : Tous les Pockets
Sujet : Sharp PC-1211/TRS-80 PC-1 Software
Réponses : 5
Vues : 1587

Re: Sharp PC-1211/TRS-80 PC-1 Software

Nice work. Bravo!

- Robert
par engelen
03 mars 2023 21:32
Forum : Silicium in English
Sujet : SHARP:USB-cable HW-handshake
Réponses : 13
Vues : 32600

Re: SHARP:USB-cable HW-handshake

For the G850V/S the RTS-pulldown resistor mentioned above is essential (10-100kOhm). Without it the G850 can‘t reliably pause transmissions from the host, just as you experienced.
Yes, I already did that and have the resistor as shown in the pictures in the HP Forum thread. But after several hours tinkering I found that the FTDI driver for MacOS M1 machines has a bug. There is no other explanation. MacOS Intel works fine. Windows machines too. I also tried 3.3V and 5V FTDI cables and different FTDI feathers, but makes no difference (although 3.3V works best, since 5V may have an issue as described earlier). It's the damn driver. The latest FTDI driver for MacOS M1 machines fails. It doesn't respect RTS. Others may not have had this issue if they are using an older FTDI driver or a non-Mac M1.

- Robert
par engelen
03 mars 2023 21:20
Forum : Tous les Pockets
Sujet : Sharp PC-1211/TRS-80 PC-1 Software
Réponses : 5
Vues : 1587

Sharp PC-1211/TRS-80 PC-1 Software

119 Practical Programs for the TRS-80 Pocket Computer:
https://archive.org/details/119-practic ... b-bookspdf
I've translated the 119 programs to source code and wav files for easy loading:
https://github.com/Robert-van-Engelen/1 ... t-Computer

TRS-80 Pocket Computer Programs:
https://archive.org/details/Pocket_Comp ... 81_Artsoft

Pocket Computer Programming Made Easy:
https://archive.org/details/Pocket_Comp ... Publishers

Bad LCD?
This can be fixed! It is not too difficult to do:
https://www.tindie.com/products/halfbak ... p-pc-1211/

- Robert
par engelen
14 févr. 2023 22:58
Forum : Silicium in English
Sujet : SHARP:USB-cable HW-handshake
Réponses : 13
Vues : 32600

Re: SHARP:USB-cable HW-handshake

After constructing an FTDI adapter for a PC-G850VS, I found that the FTDI driver 1.5.0 for Mac M1 machines fails to respect the FTDI CTS input. Without respecting the handshake, the PC keeps sending to the PC-G850VS and data will get lost. The FTDI drivers for Windows and Mac Intel machines work fine, but the driver for Mac M1 fails. Perhaps a bug.

Also, what is your recommendation with respect to 3.3V versus 5V FTDI adapters? I used a FTDI 5V adapter (Adafruit FTDI Friend) but it didn't work to send from the PC-G850VS to the PC or Mac (with inverted TXD, RXD, CTS, RTS and with CTS/RTS handshake.) Strangely, when I manually disable DTR then it works, which should have nothing to do with CTS/RTS handshake. On the other hand, there is no problem at all with the FTDI 3.3V adapter, but the 5V gives this strange behavior to block sends from the PC-G850 unless DTR is cleared manually.

Here is a longer post on the HP forum: https://www.hpmuseum.org/forum/thread-1 ... #pid169250

- Robert
par engelen
07 déc. 2022 15:15
Forum : Tous les Pockets
Sujet : FORTH for the PC-G850(V)(S)
Réponses : 8
Vues : 2646

Re: FORTH for the PC-G850(V)(S)

The smaller "standard 8K version" Forth850 has proven to be stable for weeks of using it with aggressive testing, but lacks floating point.

The work-in-progress Forth850 "full version" with IEEE 754 floating point had an issue with floating point string parsing that I fixed today. Testing the "full version" of Forth850 with IEEE 754 floating point will continue before I am confident to upgrade from v0.9 to a stable v1.0.

Further work on the IEEE 754 floating point implementation is progressing well. I have a new prototype of the Forth850 "full version" with IEEE 754 floating point that implements three of the five IEEE 754 rounding modes to choose from: round to nearest, ties to even (same as libmath used by C/C++, Lua, Python, Julia etc), round to nearest, ties to away, and round towards zero (truncation). The "full version" of Forth850 will use round to nearest, ties to even. The Z80 math code base is still small and efficient, i.e. "memory less" using Z80 registers. The rounding modes add about 67 bytes of code after rewriting parts of the Z80 core IEEE 754 math routines.

Creating clean, well-documented and formalized Z80 assembly code helps a lot to assure the IEEE 754 math implementation is correct. It's an interesting and fun small project to work on!

- Robert
par engelen
29 nov. 2022 22:00
Forum : Tous les Pockets
Sujet : FORTH for the PC-G850(V)(S)
Réponses : 8
Vues : 2646

Re: FORTH for the PC-G850(V)(S)

engelen a écrit : 19 nov. 2022 02:43 I'm also looking for a floating point library that is small. There are some Z80 floating point projects that might be suitable. But the code base is typically quite large. In other cases the Z80 code looks specific for certain platforms, like the Ti-83. If I can't find a fp library, then I may write my own. I already wrote some fp routines that are single precision IEEE 754 compatible.
New Z80 IEEE 754 floating point library is complete and now added to the Forth850-full version. The full version is a 10K binary. The small version is 8K.

I've tested the floating point routines and wrote some demo code. Here a sine plotter that uses the new Z80 floating point routines:

Image

The IEEE 754 floating point implementation is close to compliance, but lacks INF/NAN support (since Forth has exceptions we get errors any way) and does not use "banker's rounding" (to avoid code bloat). There is no observable difference, except for the rounding of the last (binary) digit. I may revisit this sometime in the future.

- Robert
par engelen
22 nov. 2022 19:00
Forum : Tous les Pockets
Sujet : FORTH for the PC-G850(V)(S)
Réponses : 8
Vues : 2646

Re: FORTH for the PC-G850(V)(S)

I made some further Z80 math speed improvements and fixed a bug in the '*' (star) multiplication word.

So far everything tested out OK, but will keep v0.9 version until I'm sure there are no remaining issues. Then I will update to v1.0.

- Robert
par engelen
19 nov. 2022 02:43
Forum : Tous les Pockets
Sujet : FORTH for the PC-G850(V)(S)
Réponses : 8
Vues : 2646

Re: FORTH for the PC-G850(V)(S)

Gilles59 I have no problem if you or someone else wants to port the code as long as credits are included. It is BSD-3 open source and fully documented. The only system calls that are required are calls similar to PUTCHR to write a character with EMIT and GETCHR to read the keyboard with KEY (and GETKEY) in Forth. These are easy to replace.

I'm also considering porting Forth850 to the PC-1600, perhaps sometime soon. In the meantime, I'm also looking for a floating point library that is small. There are some Z80 floating point projects that might be suitable. But the code base is typically quite large. In other cases the Z80 code looks specific for certain platforms, like the Ti-83. If I can't find a fp library, then I may write my own. I already wrote some fp routines that are single precision IEEE 754 compatible.

- Robert
par engelen
15 nov. 2022 02:59
Forum : Tous les Pockets
Sujet : FORTH for the PC-G850(V)(S)
Réponses : 8
Vues : 2646

FORTH for the PC-G850(V)(S)

A modern Forth 2012 standard compliant system for the Sharp PC-G850(V)(S) pocket computer.

Image

Download here: https://github.com/Robert-van-Engelen/Forth850

You can extend Forth850 as you wish, including assembly code written on the machine itself in the TEXT editor and assembled with the built-in Z80 Assembler. Forth source code can be written with the built-in TEXT editor to read it back into Forth with the TEXT word.

I've implemented Forth850 as efficiently as possible in direct threaded code (DTC) with brand new Z80 code written from scratch. The Forth850 source code is included and heavily documented.

The n-queens benchmark is solved in 0.865 seconds, the fastest Forth implementation of the benchmarks. Forth850 n-queens runs 5 times faster than the C n-queens benchmark on the PC-G850VS.

Forth850 includes stack under/overflow checks, dictionary overflow checks and can be interrupted by pressing BREAK.

I'll be happy to take requests for new features and include additions, demos and examples.

- Robert
par engelen
16 sept. 2022 21:00
Forum : Tous les Pockets
Sujet : Forth for the PC-E500(S)
Réponses : 1
Vues : 1152

Forth for the PC-E500(S)

Forth500 is a standard Forth system for the Sharp PC-E500(S) with 564 built-in Forth words.

The new version 2.0 runs up to 20% faster than version 1.0 by exploiting faster 16-to-20 bit address conversion via the internal RAM registers of the ESR-L CPU.

The well-known NQUEENS calculator benchmark finishes in 3.47 seconds in Forth500 2.0. It took 4.15 seconds in Forth500 1.0.

The speed boost should be noticible to colon definition calls (20% less overhead) and also to all Forth primitives involving single and double integer literals, variables, values, constants, single and double integer store and fetch, single integer arithmetic involving addition and subtraction, and single and double integer stack operations.

Improvements are also made to the Forth500 manual and to the Forth500 implementation overall, including new support for Forth vocabularies (yes, finally...)

Also included in Forth500 2.0 is a new text editor "TED". TED.FTH is located in the Forth500 additions folder. With TED you can interactively write, edit and run Forth code in Forth500.

Enjoy!

- Rob
par engelen
16 juil. 2022 15:34
Forum : Tous les Pockets
Sujet : Lisp in 99 lines of C for the Sharp PC-G850
Réponses : 5
Vues : 2373

Re: Lisp in 99 lines of C for the Sharp PC-G850

Hi G.E.
Thanks for the comments!
Sure, you can rewrite it and port the C code in any way you want. You have my permission.
Please post back on your progress. Happy to help if needed.

- Robert
par engelen
15 juil. 2022 22:37
Forum : Tous les Pockets
Sujet : Lisp in 99 lines of C for the Sharp PC-G850
Réponses : 5
Vues : 2373

Re: Lisp in 99 lines of C for the Sharp PC-G850

Appreciation for Lisp grows over time :)

Lisp is interesting once you write an interpreter for it or studied the internals in its simplest, purest form. That's what this little project is about.

Otherwise, Lisp is just awkward syntax!

- Robert
par engelen
15 juil. 2022 21:15
Forum : Tous les Pockets
Sujet : Lisp in 99 lines of C for the Sharp PC-G850
Réponses : 5
Vues : 2373

Lisp in 99 lines of C for the Sharp PC-G850

I wrote a Lisp interpreter for the Sharp PC-G850(V)(S) in 99 lines of C with an article explaining the inner workings of Lisp in detail:

tinylisp on GitHub

The C program compiles and runs on the PC-G850(V)(S) itself:

Image

Might be a fun way to learn Lisp :D

- Robert

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