Projects

GRAD-A01 - Micropower Geiger-Müller Counter Arduino Shield

Submitted by GG on Mon, 10/12/2020 - 11:47

A new version of this project is available here

GRAD A01Like many other hobbyist we have always been fascinated by radioactivity and the sensors to detect it. Geiger-Müller tubes are a common and relatively inexpensive way to measure radiation. GRAD is a complete solution for radiation counting in an Arduino shield form factor. Its main features are dual tube support to increase sensitivity and very low power consumption.

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NUPS - MCU UPS with NiMH Batteries

Submitted by GG on Wed, 06/17/2020 - 22:44

NUPS A00Many MCU applications are portable and need a mean to provide power on the go. There are many solution based on Li-ION and Li-Polymer batteries. However Lithium chemistries need sophisticated charging and protection circuits to avoid dangerous situations. For lower power projects NiMH batteries provide a simpler and safer alternative. NUPS (NiMH UPS) can provide 3.3V and 5V using 1 to 3 AA or AAA NiMH cells.

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ISO01 - Compact low voltage isolated power supply

Submitted by GG on Sat, 05/23/2020 - 23:14

ISO01 A00While working in the lab it's often useful to have a small isolated power supply handy. Depending on the circuit configuration, ISO01 can generate galvanically isolated unipolar and symmetric voltages from a single 3.3V or 5V rail. The circuit is based on the Texas Instruments SN6501 transformer driver and uses an easy to obtain off the shelf transformer.

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GRAD-A00 - Micropower Geiger-Müller Counter Arduino Shield

Submitted by GG on Sat, 04/11/2020 - 13:22

A new version of this project is available here

GRAD A00Like many other hobbyist we have always been fascinated by radioactivity and the sensors to detect it. Geiger-Müller tubes are a common and relatively inexpensive way to measure radiation. GRAD is a complete solution for radiation counting in an Arduino shield form factor. Its main features are dual tube support to increase sensitivity and very low power consumption.

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GZ/80S-B00 - 20MHz Z-80 PCPI Applicard compatible Apple CP/M card

Submitted by GG on Thu, 04/02/2020 - 02:19

A new version of this project is available here

GZ80 B00The PCPI Appli-Card was the first single board computer style CP/M card for the apple II. It featured a 6MHz Z-80 CPU paired with 64KB of RAM and 2KB of ROM. Thanks to the high clock and zero wait states DRAM accesses the card performed almost 3 times as fast as the Microsoft SoftCard. The GZ/80-B00 is a new implementation of the PCPI card with a 20MHz Z-80 CPU and 512KB of static RAM.

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GTERM25 - DB25 Active SCSI Terminator with diagnostics LEDs

Submitted by GG on Sun, 02/16/2020 - 15:28

GTERMActive termination is required to get newer high performance drives working on vintage computers. Unfortunately both the Amiga and older Apple computers use a DB25 SCSI connector which makes finding a suitable terminator quite difficult. GTERM25 solves this problem providing a high performance active terminator with a DB25 connector and SCSI diagnostic LEDs.

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GZ/80-A03 - Zilog Z80 turbo card for Apple II computers

Submitted by GG on Thu, 01/30/2020 - 09:57

A new version of this project is available here

gz80The Microsoft Softcard was the first card to allow CP/M software to run on the Apple II. It was originally developed to simplify the porting of Microsoft Basic to the Apple II. It turned out to be a great success and at some point in time it was the most popular CP/M platform in use.
This success prompted the development of many compatible cards. Some exact copies, some enhanced or cost reduced. The GZ/80 is a modern implementation of a Softcard compatible card with an additional turbo mode with approximately double the speed of the original card.

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A2SCSI-A01 - Apple II SCSI card clone

Submitted by GG on Sat, 10/19/2019 - 17:50

A new version of this project is available here

A2SCSI FrontThe Apple II SCSI card from 1986 was one of the first interface cards to attach a Hard Disk Drive to the Apple II line of computers. A2SCSI is a clone of the last revision (rev.C) of the card with a few enhancements to improve compatibility with modern SCSI drives.

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