Anyone that knows me will remember my interest in Laserdisc, especially when linked to a PC. This very early PC World article shows a time when even the definitions of the techology and it’s applications were evolving.
Presented below are painstaking scans from PC WORLD 1984-10 and nice PDF available as always on Google Drive: Scanned Book and Magazine Collection -> Laserdisc (folder). Or browse low res images below:
A recent donation brought alone these rare, late 1970s service manuals and schematics. Difficult to scan but we got there. Teleray 3500 and Teleray 3500 C1 are covered. I am sharing these as there is a lot of narritive that explain to you a fascinating chain of electronics that go into making a terminal work. Highly educational and worth of a scroll through by anyone.
Scanned Book and Magazine Collection -> Service Manuals and Repair Books (CRT monitors, data terminals)
This service manual provides complete servicing and adjustment information for the TELERAY 3500 series CRT Data Terminals. It is assumed that the reader has both a general background in electronics and a knowledge of digital communications and circuitry.
Please read this manual before attempting to service a TELERAY. Note that appropriate test equipment is required for some adjustments.
WARNING: High voltages injurious to health are present inside the TELERAY, particularly in the vicinity of the CRT monitor. Use extreme caution when working on the unit.
CAUTION: Certain of the integrated circuits used in the TELERAY are MOS ICs; although they are input-protected, use standard MOS handling procedures when working on the circuitry, particularly the 2513 Character Generator ROM.
1od OPERATIONAL DESCRIPTION
The TELERAY 3500 series CRT Data Terminals are communications-oriented units providing transmission and reception of character-oriented data. Data is entered: either from
the keyboard at the front of the terminal or from a standard data interface, and is displayed on the CRT screen. Characters are displayed at the bottom of the screen and each line of information ” scrolls ” upward as the next line is entered. The screen can display 24 lines of up to 80 characters per line. The character set consists of
64 displayed and 98 generated ASCII characters. A cursor indicates the next data entry position; it can be moved left or right with or without the Space-Over-Data function
( described elsewhere ).
INTRODUCTION TABLE OF CONTENTS Introduction 1 Operational Description Specifications General Communications Interface Display Format Functions Provided Operator Controls .1 Control Descriptions INSTALLATION Installation Power Line Connections Interface Connections RS232C Communications Interface Current Loop ( 20 ma. ) Interface TTL Logic Interface Optional Printer Output Optional Composite Video Changing Formats and Features Setting Baud Rate Connecting a TELERAY to.a Teletypewriter MAINTENANCE 3.0 Maintenance TELERAY THEORY OF OPERATION General System Orientation/Organization Power Supply Theory of Operation Keyboard Theory of Operation Logic Theory of Operation – Introduction Timing Section Memory Section Input/Output Section Notes on Asynchronous Data Transmission USA Standard Code for Information Exchange TELERAY Display Font Timing Waveforms TROUBLESHOOINTG 5.0 5.1 5.2 5.3 5.4 5.5 Fault Isolation No Characters Displayed Incorrect Display Intermittent Problems 1/0 Problems Power Supply Problems SCHEMATICS ASSEMBLY – TELERAY LOGIC BOARD SCHEMATIC – TELERAY CRT TERMINAL TIMING AND PM COUNTER LOGIC SCHEMATIC – TELERAY CRT TERMINAL MEMORY 96 CHARACTERS SCHEMATIC – TELERAY CRT TERMINAL SERIAL I/0 ASSEMBLY – PRINTED WIRING BOARD – TELERAY ( Power Supply ) SCHEMATIC – POWER SUPPLY, TELERAY KEYBOARD SPECIFICATIONS KC44701 KD44702-1 KD44702-2 KD44702-3 KD44704 C44705 53SW1
First published 1983 by William Collins Sons & Co Ltd Written and designed by Robin Kerrod Illustrations and diagrams by Ian McIntosh, John and Mike Gilkes, Bryan Foster.
I found this book at a local op-shop and couldn’t pass it by. The books narrates a wide range of technologies from the 1980s. Subjects are at the TOC:
Consider your PDF view, can you set it to two-page zoomed to fit?
Some PDF viewers add a ‘seam’ down the middle, others perfectly join the left and right pages together. FoxIt PDF viewer is particularily good for two-page views. I consider this PDF an essential ‘scroll through’ as it is full of photographic examples of how computers are applied in industry (of the eighties). Aimed at all ages – not just children.
Printed pages match PDF page numbers; lossless OCR engine by Tesseract 4.0, my magic.
The aim of this essay (jokes) is to introduce the GBS-Control project to vintage computing enthusiasts that want to use modern displays with their computers. It will begin with components to buy and then list the hardware modifications and install steps. Later I rationalise the benefits of this implementation, especially for the Apple IIGS computer. Step by step instructions are provided, along with photos and commentary.
If you are a visual learner, scroll to the end of this post and click through all the captioned photos instead.
GBS8200 originates as a mass-produced video scaling board that supports analogue RGB video standards that were commonly used in arcade games and gaming consoles from the 1980s. It is low cost hardware based on the TVIA TrueView 5725 scaling chip. It is controlled by a Myson MTV230GMV microcontroller and has 64mb SDRAM.
Inputs are RGB video with Composite Sync preferred (C-SYNC), or Component Video (Y Pb Pr). 15Khz / 240p / 480i and 31khz 480p is supported. The output is always RGBHV with TTL level sync that is buffered by a TI 74HC125. Power input can range from 5-12volts and draw, with ESP8266 connected and on, is approximately 450mA at 5v.
Of most intrigue is the debugging / System Programming mode jumper setting and SCL/SDA accessibility. The board seems to be designed for modification. Especially considering the poor performance when left unmodified / stock firmware.
Video standards are rapidly changing to accommodate advancements in resolution and display devices. This can be seen from the 1950s with NTSC designed to accommodate colour video transmission through to 2020 with HDMI accommodating 4K 120fps HDR digital video signals. The 1980s saw video standards evolve with home computers to move from composite video on the Apple II, S-Video on the Commodore 64 and 15KHz analogue RGB C-SYNC on the Apple IIGS and Commodore Amiga. IBM transitioned through CGA/EGA/VGA standards which further brought connection and sync changes. It is hard to keep up!
Scaling is a broad term that means a low resolution image is upscaled to a higher one. Home theatre enthusiast have used scalers to clean up video and upscale it to better suit their display (e.g projector). Until recently the market revolved around video scaling / format conversion but failed to cater for the unique RGB video formats in vintage computers. Products by DVDO and Extron were a gold standard for home theatre and cost thousands of dollars. Scalers sold in 2020 can cost thousands of dollars and are designed for digital format conversion and rarely have the RGB input that we need.
Only in recent years have more scalers emerged on the market to better support scaling of non-video (e.g. 480i) signals. The Open Source Scan Converter (OSSC) is approximately $250 AUD and supports a wide range of RGB video signals such as those from the Apple IIGS and Amiga. However versatile it may be, it has many shortcomings such as issues locking onto a stable IIGS picture and cost. A flagship feature of the OSSC is it only supports integer scaling in line multiples, which creates a major problem for display compatibility the output is not a standard CMT/VESA resolution. GBS Control offers a range of standard 4:3 output resolutions such as 640×480 (2x), 1280×960 (4x) and 16:9 1920×1080 (non-integer).
For home computers that use the analogue RGB standard, we have the added complexity of specific video formats that can change. The Apple IIGS has both 50 and 60hz support, along with low and high resolution modes. The Commodore Amiga has even more video modes that support progressive and interlaced output. Video scalers have been geared towards supporting deinterlacing video signals opposed to scaling progressive video from a home computer at high speed. This leads to a wide range of problems such as a halving of resolution and flicker due to deinterlacing incorrectly being applied.
My understanding is an Australian electrical engineering student “dooklink” began developing a custom firmware to control the GBS8200. He needed a scaler that could scale his gaming consoles such as the Sega Megadrive for display on modern CRT monitors. The earliest date I can find is 07/11/2014 where he registered on the Shmups forum to introduce his ideas for the project. Initially he controlled the GBS8200 board with an original Raspberry Pi to program the ‘register settings in the scaling chip’.
My understanding of this project is that it quickly gained traction online and eventually moved to Github where the code has transitioned to support an ESP8266 ESP-12E based Arduino and is maintained by ramapcsx2. It’s been 6 years of changes, and I can only marvel at the online community’s participation in the project.
Very low lag: Undetectable added delay, measured at less than 7 milliseconds (!). For example, when the mouse is moved, it will display onscreen as you would expect. Poor scalers will add up to 100ms of ‘lag’ which makes moving the mouse like a block of soap.
Sharp and defined upscaling: The custom firmware scales by integer to best promote equal line widths and geometry. One preset outputs 1280×960 pixels which is a perfect integer x4 scale, or for compatibility it can output 1920×1080.
Useful features and image enhancements: The picture can easily be moved and resized in any direction. The firmware automatically adjusts the AGC (automatic gain control) for brightness adjustments each time the input changes/scaler turned on. ‘Peaking’ ensures sharp digitization of the video by normalising peaks of voltage transitions.
WiFi control built in. While it can automatically run unattended and offline, you can easily control the scaler using a web browser.
The Apple IIGS outputs 0.5v p-p analogue RGB video with clean Composite Sync at 4v, with a pixel dot clock of 16mHz. These non-standard specifications were suited to the matching Apple RGB monitor only, and present a challenge for most scalers to ‘get right’. In my experience of scaling this output to HDMI using the Extron RGB-HDMI 300 and Open Source Scan Converter has been a little frustrating. I lost countless hours tweaking the input parameters such as pixel phase to achieve a clear desktop/Finder image but a resolution change would cause things to go out of phase again.
The GBS8200 with GBS-Control custom firmware offers complete compatibility with the Apple IIGS video output. I have demonstrated this in short YouTube videos demos based on extensive personal testing. It is the only solution that I’ve tested that correctly and automatically adjusts for 40/80 column video modes, higher resolution Apple II colour modes (in RGB) and the Finder, providing flicker free square pixels. What a revelation!
Cost: There simply isn’t a product or solution on the market that can offer compatibility as described for approximately $80 Australian dollars.
Availability: If one was to use an Extron/Kramer scaler then you’re facing a second hand market with variable pricing and some units over 10 years old. The GBS8200 is still mass produced in China at low cost, as is the ESP8266 Arduino.
The next step: The scaled video output is RGBHV from either a JST connector or VGA/HD15 port. Modern display devices feature HDMI as a convenient connection, and we now use a low cost VGA to HDMI transcoder to output the scaled video as HDMI with sound. Simply connect the supplied cable from the headphone output of the IIGS to the adapter sound in jack. I have tested a widely available (pre-COVID) device that is based on the MSP9282 chipset by Hefei Macro Silicon technology. It features a claimed 10-bit per channel ADC for sampling the video to digital and outputs a HDMI compliant signal. Simply connect the supplied cable from the headphone output of the IIGS to the adapter sound in jack.
Implementation: The GBS8200 board from factory requires basic hardware modification and an ESP8266 to be programmed and connected. For newcomers I would expect some difficulty following the whole project as it’s a lot to take in. In months to come you’ll wonder why you didn’t try this earlier!
Quality wire for connecting the scaler to controller (remember video and power wire is supplied).
Rosin or No-clean flux and copper braid for de-soldering. Multi-layer PCB and lead free/thick solder from factory. Avoid excessive force in removing components. Alternatively/not expected, use a desoldering pump+iron with flux and you’ll easily move on to the next step
Small snips for cutting out RP1,2,3 if not de-soldering (remember the lead free/thick.
Clipped leads from axial capacitor / anything to make a 4 sets of a 1cm jumper bridge (enables debug mode and connects RP pads)
Hot glue / snot for daub of strain relief on certain wires
We have up to three active components to power from a single source and therefore strictly use +5v for input to the 2.1mm barrel jack (center positive). JST Connector P9 traces directly to the directly to barrel jack input P7. The included wire for P9 can be shortened and soldered to the controller’s VIN and GND pads to supply it with +5v. Then flip the board over to add a microUSB cable to the + and – pads of P9. Discussed below.
Controller ~150mA (max)
Transcoder ~20mA (ultra low current/draw).
The HDMI transcoder comes with a microUSB to USB-A cable and this can be modified to run from the scaler board. One can cut the USB-A port off and strip the cable back to reveal a red (Vcc) and black (Gnd) wire, to be soldered to the scaler. Flip the board over, solder the underside of P9 for VCC and GND. Please check continuity throughout. This gives you a microUSB cable with +5v on it that is long enough to reach the transcoder.
Remove the orange pots RP1, RP2, RP3 and then bridge them (the lower left pad to the top). This avoids low brightness and colour tint problems.
Add a 470-ohm resistor across sync and ground. The Apple IIGS outputs a relatively strong sync signal and we want to avoid the scaler’s 3.3v logic level chips being overloaded with our unregulated sync input. This modification is easily achieved. Simply solder this resistor on either side of the scaler across sync and ground poles on the left of the board. See photo. Rationale in appendix.
Replace C11 with 22uf 6.3v (or higher voltage tolerance) electrolytic capacitor. I like to clean the pads of C11 and leave it unused, in favour of soldering directly to the LDO as show in my photos. Right sided pin is negative – we are moving from ceramic to electrolytic so observe polarity by continuity testing the left and right side of the pads to ground.
Bridge/close P8 (programming port). Simply bridge this on the underside of the board. No need to nick a jumper from an old hard drive.
Tin the MTV230GMV debug pin 30. This is for connecting to D6 of the controller/ Arduino. This allows control of TrueView chip registers.
In summary we remove 3 pots, add a resistor, upgrade a capacitor and bridge P8. Easy! Compare ze market .com.au!
In all seriousness though the removal of RP1,2,3 is the most time consuming step. The thin board may lift a pad and this is easy to fix. Do not worry if a pad lifts as there is always at least one other spot to use in it’s place.
ALL Arduinos from me have been pre-programmed with GBS-Control firmware and are ready to solder in place.
Otherwise, Program your Arduino as per instructions on Github. This requires the firmware project files, programming software and miniUSB B cable. Personally the Arduino programming was worked well but again did require a level of specificity these boards are famous for. E.g setting CPU speed and flash size. A PDF version of the Github based instructions are provided in the appendix as a PDF file. For further simplicity, I have copied a summary as written by ‘Syntax’ to the appendix also.
The Is Si5351 Clock Generator board is controlled by I2C to output precise frequencies from <8KHz up to 150+ MHz. Input VCC is 3-5v and output is 3vpp. The GBS-Control firmware automatically supports this board when installed as follows:
Solder a wire from the centre pad of CLK0 to TrueView pin 40 (PCLKIN). Check for continuity and resistance. Remember only the centre pad for CLK0 is for signal. In my board I have used prepared AWG32 enamelled copper wire.
With the scaler board oriented with text facing you, the left side of either C47 or C48 can be used for ground when soldered to the first or third pad of CLK2. I used AWG30 Kynar with the smallest amount of exposed wire, flux and a small amount solder.
For powering the clock gen, solder a wire from the positive side of either C47 or C48 to the unlabelled capacitor shown on the clock gen board. It is most likely a filtering capacitor for the clock’s LDO 3.3v output. Again I have used AWG30 Kynar wire and clear varnish for fixation to the PCB.
The Myson Controller (MTV230) is connected via
– Pin 15 (P3.0/Rxd/HSCL) to Si5351 SCL
– Pin 16 (P3.1/Txd/HSDA) to Si5351 SDA
This can be achieved by soldering directly to each controller IC leg (no lift) as I have done.
Alternatively one use the output side (right) of R10 for SCL and R37 for SDA. Add strain relief.
To test the clock generator is working, open the GBS Control web gui. Go to Preferences and scroll down to Activate FrameTime lock. Press on the FrameTime Lock button and the console will read “Active FrameTime Lock not necessary with external clock gen installed”. Video output should be pristine and free of horizontal tearing when high output resolution presets are used.
“Do not connect the sync output of an Amiga or a LM1881 sync stripper direct to a GBS-82XX board. Both devices have a logic 1 level of >4.6V! The maximum input voltage for the TVIA-5725 device is 3.6V. If you exceed the absolute maximums, you start activating the ESD protection diodes on each input, never a good idea. The excess voltage is clamped to the device internal supply by these diodes, so the 3.3V internal (to the TVIA-5725 device in this instance) gets spikes every time the input is exceeded, pulling up it’s supply. This does affect the normal operation of the device and reduces reliability. Simply connecting the CSYNC output of an Amiga or the Composite sync output of an LM1881, to the GBS-82XX board, via a 680 ohm series resistor, removes this problem. I measured a signal amplitude of 3V.”
A recent donation has awoken my scanning interests and today we have another 16 scans added to my publicly shared repository. All 16 are not known to be on Archive.org and I will make a mirror there soon. Of great interest were the huge Berkeley newsletter books. Presented here are 600dpi scans with Tesseract 4.0 neural network OCR applied.
Australian Mac users were well supported with the bespoke evalgesim of local MUGs. Berkeley (American) is on another level though, never have I seen such a valuable resource in one place. From just the two titles donated, we have over 600 pages of historic Macintosh information. Being more user focused, one can read a wide range of letters to the group that ask questions or seek solutions to bugs. Reading these BMUG scans will immediately bring back that unique pleasure and pain of being a Macintosh user – facing expensive accessories, printer bugs and getting good value software. You’d think your Macintosh was limitless in it’s capacity, from scanning photos in dithered black and white to MIDI music playing, its all there.
If you’re a Mac enthusiast or nostalgic for the era of Compact Mac, do yourself a favour and download a BMUG newsletter from my repo. I prefer syncing PDF files to my iPad via “Foxit PDF reader” (free).
Find these under Scanned Book and Magazine Collection -> Magazine Scans -> Berkeley
Raft-Away River is a game for 2 to 6 players. It is a special
sort of game called a simulation. This means that the
computer shows you a model of an adventure and you can
experiment to see what you could do if you really had such
an adventure. But, unlike the real thing, you can’t come to
any harm in a simulation. So, if your plans don’t work out
as they should, you have a chance to try again using some
different ideas. If you think hard about why your plans didn’t
work, then you might learn why some plans fail. Of course,
you will also learn how some other plans work’
First published 1984 by
THE JACARANDA PRESS
65 Park Road. Milton, Old 4064
140A Victoria Road, Gladesville, N.S.W. 2111
90 Ormond Road, Elwood, Vic. 3184
4 Kirk Street, Grey Lynn, Auckland 2, N.Z.
A product of Jacaranda Software
Program designers: Rosanne Gare and David L. Smith
Production editor: Wynrie Webber
Apple version programmed by Gerald M. Wluka
BBC version programmed by David L. Smith
Commodore 64 versions programmed by Philip O’Carroll
Microbee versions programmed by Gerald Preston·
The following information aims to help someone recap their Commodre Amiga 1000 power supply. Specifically the CA1000PS/EC by Shindengen Electric Japan. 240V PAL models. I understand the fan can be replaced with AC type only.
WordPress has no real control over table layout I suggest copying the table below into a spreadsheet and adjusting column width for your own use. The furthest right 2 colums are designed to concatenate (ancient Excel expression) the uF and V columns which allows me more easily search online stores for the values I need. Simply copy and paste the completed string and order the quantity shown in the Order column.
CA1000PS/EC Commodore Amiga 1000 Power Supply by Shindengen Electric; 240V
The aim of this blog post is to highlight four new books that I have scanned to PDF files for sharing online. Today we have:
BASIC computer programs for the home by Charles D.Sternberg
This book covers a very ride range of programs that seem to solve a number of problems such as making Christmas card lists, music collections and meal planning. For example the second chapter Automobile Related Programs covers:
Auto Maintenance 50 Gasoline Use Computation—Basic Version 54 Gasoline Use Computation—Extended Version 56 Automobile Comparisons 59 Trip Planning—Basic Version 64 Trip Planning—Extended Version 67
Navigate through the link above as Scanned Book and Magazine Collection -> BASIC Reference and Programming
2. Program Design by Peter Juliff (Head, Department of Computing Victoria College Prahran Campus Victoria, Australia)
Typed below is the table of contents (see the PDF for the illustrations!)
Writing Programs Algorithm Design Program Structure Module Design Programming Standards Program Documentation Program Testing/Debugging Serial File Processing Array Processing Abstract Data Structures Data-driven Programs Appendix A COBOL Appendix B BASIC Appendix C Pascal Appendix D
Navigate through the link at the top as Scanned Book and Magazine Collection -> BASIC Reference and Programming
The purpose of this book is threefold, to acquaint the reader with the hardware of the Z-80, to discuss the almost overwhelming (in number of instructions) software aspects of the Z-80, and to describe microcomputer systems built around the Z-80.
I bought two Z80 books and have created a new genre section on the shared Google Drive. Navigate through the link at the top as Scanned Book and Magazine Collection -> Z-80 Zilog Programming and Reference Books
This is an excellent title for looking back on hardware of the era, such as the Nano (NBZ80) and Super Nano COMPUTER (NBZ80S). It also covers in depth Z80 addressing modes, logical instructions and more.
Navigate through the link at the top as Scanned Book and Magazine Collection -> Z-80 Zilog Programming and Reference Books