BeebSCSI 7_7

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simoni
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BeebSCSI 7_7

Post by simoni » Sat May 26, 2018 1:58 pm

BeebSCSI has a newly designed (KiCAD) PCB now available that is smaller and designed for both internal mounting (in the BBC Master) or mounting in an external case:

Github - https://github.com/simoninns/BeebSCSI
BeebSCSI documentation - https://www.domesday86.com/?page_id=689

The new design also allows for right-angled IDC and other headers to be used (in order to fit better in the Elk AP5 expansion as well as other mounting applications where a <12mm height is preferable).

BeebSCSI 7_7 -  Side 1.jpg

I'll be making a 2_4 release on Github shortly (the board is firmware compatible with the 7_5 version and the 'unofficial' BeebSCSI 'mini' version, but here are the highlights of the new PCB design:
  • Smaller PCB (66 x 51mm)
  • Four M3 mounting holes (fits both Master AIV slot as well as external case mounting)
  • Straight and right-angle configuration (all sockets and headers can now be right-angled if required)
  • Single JTAG programming chain with shared header (between AVR and CPLD)
  • Support for Tag-Connect programming adapters
  • Fiducial markers for pick-and-place manufacturing compatibility
  • All components on top-copper layer
  • Improved silkscreen with better component orientation markers
  • Design rebuilt using KiCAD rather than (closed-source) EagleCAD
  • New microSD socket (provides overhang of the microSD card for better internal and case mounting options)
  • All active and passive component SMT (except headers and connectors)
  • JST-EH power connector to prevent incorrect cable orientation
  • USB to AVR header with required USB support components (to support future expansion)
  • All SMT passives now 0805 footprint
As before, the design (both hardware and software) is completely open-source and you are free to use, modify and build upon the design.

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ask_nz
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Re: BeebSCSI 7_7

Post by ask_nz » Sun May 27, 2018 7:23 am

=D>

Ade
Ade

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simoni
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Re: BeebSCSI 7_7

Post by simoni » Sun May 27, 2018 7:41 am

There is also a new version of the BeebSCSI firmware available now (V2.4):

https://github.com/simoninns/BeebSCSI/releases/tag/V2.4

This release adds enhancements to the debug output (to assist people making boards) as well as PWM brightness control of the status LED. Now, instead of flashing on and off, the LED glows with minimum brightness to show the board is powered and ready. On activity the LED shows full brightness and then fades off. Not much of a feature enhancement, but it sure looks nice :)

As usual you can simply grab the release files and use the BEEBSCSI.BIN to upgrade the firmware via the microSD card. This firmware version is compatible with all variants of BeebSCSI (7_5, 7_7 and the 'mini').

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