SCSI2SD: Difference between revisions
Michael moved page SCSI2SD to SCSI2SD old: This page is now for historical reference only, and does not necessarily describe the device as-built. |
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# | <p><strong>The SCSI Hard Drive Emulator for retro computing.</strong></p> | ||
== News == | |||
<p> | |||
<strong>10 Sep 2013:</strong><br /> | |||
It works! | |||
I have a working prototype that works well. There are a few minor errors in the PCB layout that will be fixed in the next revision. | |||
</p> | |||
== Overview == | |||
Traditional hard drives last 5 years<sup>*</sup>. Maybe, if you're luckly, you'll get 10 years of | |||
service from a particular drive. The lubricants wear out, the spindles rust. | |||
SCSI2SD is a modern replacement for failed drives. It allows the use of vintage | |||
computer hardware long after their mechanical drives fail. The use of SD memory cards | |||
solves the problem of transferring data between the vintage computer and a | |||
modern PC (who still has access to a working floppy drive ?) | |||
<sup>*</sup>All statistics are made up. | |||
== Features == | |||
# In-built active terminator, enabled by a jumper. | |||
# Can optional supply terminator power back to the SCSI bus | |||
# Selectable SCSI ID | |||
# Emulates a non-removable hard drive for maximum compatibility. | |||
== Technical Specifications == | |||
{|border="1px" | |||
|SCSI Interface | |||
|SCSI-2 Narrow 8-bit 50-pin connector. Supports asynchronous transfers only. | |||
|- | |||
|SD Card Interface | |||
|Standard SDSC (1GB maximum size)<br /> | |||
SDHC (32GB maximum size)<br /> | |||
SDXC cards are untested. Donations welcome.<br /> | |||
Communication is via the SPI protocol at 25MHz. | |||
|- | |||
|Power | |||
|5V via standard molex drive connector. | |||
|- | |||
|Dimensions | |||
|10cm x 10cm x 1.5cm | |||
|} | |||
== Performance == | |||
As currently implemented: | |||
Sequential read: 250kb/sec | |||
Sequential write: 50kb/sec | |||
These numbers are dreadful. I am working on updating the slow polling SD card communication to use DMA. I expect the performance to reach 1.8Mb/sec. | |||
== Compatibility == | |||
Tested with Linux (current), Apple Macintosh System 7.5.3 on LC-III, and LC-475 hardware. | |||
== Howto == | |||
* [[FormatWithBasiliskII]] Format an SD card for use with Apple Macintosh hardware using the [http://basilisk.cebix.net/ Basilisk II] emulator | |||
== Old == | |||
For historical project information see [[SCSI2SD old]] |
Revision as of 12:53, 10 September 2013
The SCSI Hard Drive Emulator for retro computing.
News
10 Sep 2013:
It works!
I have a working prototype that works well. There are a few minor errors in the PCB layout that will be fixed in the next revision.
Overview
Traditional hard drives last 5 years*. Maybe, if you're luckly, you'll get 10 years of service from a particular drive. The lubricants wear out, the spindles rust. SCSI2SD is a modern replacement for failed drives. It allows the use of vintage computer hardware long after their mechanical drives fail. The use of SD memory cards solves the problem of transferring data between the vintage computer and a modern PC (who still has access to a working floppy drive ?)
*All statistics are made up.
Features
- In-built active terminator, enabled by a jumper.
- Can optional supply terminator power back to the SCSI bus
- Selectable SCSI ID
- Emulates a non-removable hard drive for maximum compatibility.
Technical Specifications
SCSI Interface | SCSI-2 Narrow 8-bit 50-pin connector. Supports asynchronous transfers only. |
SD Card Interface | Standard SDSC (1GB maximum size) SDHC (32GB maximum size) |
Power | 5V via standard molex drive connector. |
Dimensions | 10cm x 10cm x 1.5cm |
Performance
As currently implemented:
Sequential read: 250kb/sec Sequential write: 50kb/sec
These numbers are dreadful. I am working on updating the slow polling SD card communication to use DMA. I expect the performance to reach 1.8Mb/sec.
Compatibility
Tested with Linux (current), Apple Macintosh System 7.5.3 on LC-III, and LC-475 hardware.
Howto
- FormatWithBasiliskII Format an SD card for use with Apple Macintosh hardware using the Basilisk II emulator
Old
For historical project information see SCSI2SD old