blue-gs/README.md

# BlueGS: Internal BlueSCSI for Apple IIgs and Enhanced //e

https://github.com/xunker/blue-gs

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- [BlueGS: Internal BlueSCSI for Apple IIgs and Enhanced //e](#bluegs-internal-bluescsi-for-apple-iigs-and-enhanced-e)
- [About](#about)
- [How it works](#how-it-works)
- [Features](#features)
- [Compatible SCSI cards](#compatible-scsi-cards)
- [Performance](#performance)
- [Assembly](#assembly)
- [Installation](#installation)
- [Board Pictures](#board-pictures)
- [Schematics](#schematics)
- [EDA/Kicad Files](#edakicad-files)
- [Credits](#credits)
- [License](#license)

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# About

*BlueGS* is the internal hard drive your Apple IIgs and //e always *craved*.

Using the [BlueSCSI](https://github.com/erichelgeson/BlueSCSI) SCSI drive emulator and your compatible SCSI card, you have a fully internal hard drive with accessible microSD slot while still keeping your DB-25 connector free for other peripherals.

[![Close-up of BlueGS installed in IIgs slot](images/bluegs_v1.2_rear_installed_cropped_thumb.jpg)](images/bluegs_v1.2_rear_installed_cropped.jpg)
[![BlueGS installed in IIgs slot, right side](images/bluegs_v1.2_rear_installed_right_thumb.jpg)](images/bluegs_v1.2_rear_installed_right.jpg)
[![BlueGS installed in IIgs slot, left side](images/bluegs_v1.2_rear_installed_left_thumb.jpg)](images/bluegs_v1.2_rear_installed_left.jpg)

# How it works

BlueGS connects between your SCSI card and its external DB-25 connector to give you a seamless installation. The BlueGS module itself mounts in a free DB-25 connector cutout in the rear of your IIgs or Enhanced //e.

[![Overhead view of BlueGS in IIgs slot](images/bluegs_v1.2_installed_overhead_thumb.jpg)](images/bluegs_v1.2_installed_overhead.jpg)
[![Frontal view of BlueGS in IIgs slot](images/bluegs_v1.2_installed_front_thumb.jpg)](images/bluegs_v1.2_installed_front.jpg)

# Features

* Gives your Apple IIgs or //e an internal, cable-free hard drive
* Can be powered from SCSI termination power only (if present)
* "Termination Power" mod is not required (when powered from the IIgs internal fan connector)
* Can *provide* termination power to the SCSI bus (when powered from the IIgs internal fan connector)
* Built-in termination that is controlled with a single switch
* TI/Unitrode termination ICs instead of passive termination, reduces power consumption by over 2/3rds
* Connection for external drive activity LED

# Compatible SCSI cards

Tested:
* [GGLabs A2SCSI](https://gglabs.us/node/2071) - a clone of the Apple Rev C SCSI card

Untested, but expected to be compatible:
* Apple Rev C SCSI and clones
* Apple High-Speed SCSI ("Sandwich II")

Unknown, but likely compatible:
* Ramfast SCSI
* Any SCSI card that uses has the same IDC-26/DB-25 pinout as the Apple Rev C SCSI

If you have an SCSI card with an IDC-26/DB-25 connector that has not been tested and would be willing to test your card with BlueGS, please [contact us](https://github.com/xunker/blue-gs/issues) to arrange to have a test unit sent to you.

# Performance

Using [BenchmarkD](https://www.brutaldeluxe.fr/products/apple2gs/benchmarked.html) with Apple IIgs (ROM 1, "Fast" speed), GS-RAM Plus w/ 2MB, GGLabs A2SCSI card.

* Read
  * File: 52 KB/s
  * Block-by-block: 36 KB/s
  * With 64K buffer: 79 KB/s
* Write (File): 37 KB/s

# Assembly

If you purchased BlueGS as a self-assemble kit or are using your own PCBs, please follow the instructions in the "[assembly](assembly/)" directory.

If your BlueGS was purchased fully-assembled, please move on to the "[Installation](installation/)" section.
# Installation

Installation guides can be found in the "[installation](installation/)" directory.
# Board Pictures

![Rendering of front of board v1.2](images/bluescsi_iigs_internal_v1.2_front.jpg)

![Rendering of back of board v1.2](images/bluescsi_iigs_internal_v1.2_back.jpg)
# Schematics

[V1.2 Schematic](schematics/schematic_v1.2.pdf)

[V1.1 Schematic](schematics/schematic_v1.1.pdf)

# EDA/Kicad Files

Kicad of current design can be found in [kicad](kicad/) directory.

# Credits

This project would not be possible without the work done by [ztto](https://github.com/ztto/ArdSCSino-stm32), [Tambo](https://twitter.com/h_koma2), [Eric Helgeson](https://github.com/erichelgeson/BlueSCSI), and many others.

The "Blue Pill" footprint was originally created by [Yet-Another-Average-Joe](https://github.com/yet-another-average-joe/Kicad-STM32).

Symbol and footprint for Molex 105162-0001 MicroSD slot created by [SnapEDA user HMantz](https://www.snapeda.com/parts/105162-0001/Molex/view-part/).

External LED driver circuit credit to @akuker on Open Retro SCSI Discord.

# License

See [LICENSE.md](LICENSE.md).