Skip to main content

The Ohio Scientific 300 Trainer

In the late 1970s there were a host of companies that dominated the computer market before the introduction of the IBM PC. One of these was Ohio Scientific or OSI. [BradH] has an OSI Model 300 trainer — their first major product — and gives us a peek at it along with some history of the company.

Companies like OSI, Southwest Technical Products, Osborne, Northstar, and PolyMorphic were the second wave after the likes of MITS and IMSAI had opened the personal computer market. Only a few companies like Apple hung on and made it work over the long haul.

If the history lesson isn’t for you, the technical talk starts at 4 minutes into the video below the break. This is a 6502 with 128 bytes of RAM. Not 128 megabytes or even kilobytes. 128 bytes. There’s a pretty traditional front panel with switches and LEDs.

We were impressed the board is still working. The typewritten manual looks odd today, and the board reminded us of a precursor of machines such as the KIM-1 and even the old Apple computer — the one that was also a small 6502 board and is now retconned as the Apple I.

We love these little peeks at old hardware. This would be a fun one to reproduce on a breadboard. The hand-drawn PC board shows there isn’t much to connect compared to almost anything you’d build today.

Watching [BradH] flip the switches, we couldn’t help but remember our own tour of the PDP-8. That one was an emulator, but we love [Oscar’s] recreation for doing real switch flipping.



from Hackaday https://ift.tt/2RGNgQQ
Labels:

Comments

Post a Comment

Popular posts from this blog

How To Play Doom – And More – On An NES

Doom was a breakthrough game for its time, and became so popular that now it’s essentially the “Banana For Scale” of hardware hacking. Doom has been ported to countless devices, most of which have enough processing ability to run the game natively. Recently, this lineup of Doom-compatible devices expanded to include the NES even though the system definitely doesn’t have enough capability to run it without special help. And if you want your own Doom NES cartridge, this video will show you how to build it . We featured the original build from [TheRasteri] a while back which goes into details about how it’s possible to run such a resource-intensive game on a comparatively weak system. You just have to enter the cheat code “RASPI”. After all the heavy lifting is done, it’s time to put it into a realistic-looking cartridge. To get everything to fit in the donor cartridge, first the ICs in the cartridge were removed (except the lockout IC) and replaced with custom ROM chips. Some modifica...
Post a Comment
Read more

The Flexible Permanence of Copper Tape Circuits

Somewhere between shoving components into a breadboard temporarily and committing them to a piece of protoboard or a PCB lies the copper tape method. This flexible Manhattan-style method of circuitry formed the basis for [Bunnie Huang]’s Chibitronics startup, and has since inspired many to stop etching boards and start fetching hoards of copper tape. [Hales] hit the ground running when he learned about this method , and has made many a copper tape circuit in the last year or so. He offers several nice tips on his site that speak from experience with this method, and he’ll even show you how to easily work an SMD breakout board into the mix. Generally speaking, [Hales] prefers plywood as the substrate to paper or cardboard for durability. He starts by drawing out the circuit and planning where all the tape traces will go and how wide they need to be. Then he lays out copper traces and pads, rubs the tape against the substrate to make it adhere strongly, and reinforces joints and laps w...
Post a Comment
Read more

The Newbie’s Guide To JTAG

Do you even snarf? If not, it might be because you haven’t mastered the basics of JTAG and learned how to dump, or snarf, the firmware of an embedded device. This JTAG primer will get you up to snuff on snarfing, and help you build your reverse engineering skills. Whatever your motivation for diving into reverse engineering devices with microcontrollers, JTAG skills are a must, and [Sergio Prado]’s guide will get you going. He starts with a description and brief history of the Joint Test Action Group interface, from its humble beginnings as a PCB testing standard to the de facto standard for testing, debugging, and flashing firmware onto devices. He covers how to locate the JTAG pads – even when they’ve been purposely obfuscated – including the use of brute-force tools like the JTAGulator . Once you’ve got a connection, his tutorial helps you find the firmware in flash memory and snarf it up to a file for inspection, modification, or whatever else you have planned. We always apprec...
Post a Comment
Read more