Update:
inofficial MBHP_SID_V4.1
features:
-supports two MOS8580 and
-swinsid x2 compatible (this is not my brainchild, i solely announce the compatibility. i do not provide the firmware, as this is swinkels' work)
-makes a total of 4 channels
-logic chips replaced with an altera max7000 cpld to provide greater flexibility
-only requires 5V supply, as the 9V are generated on board
connectors:
4 x SMA (or SMB), one per channel
1 x 2pin external 5V
J5a and J19 for link to MBHP_CORE_32
J5a:
-/CS0 and /CS1: binary chip selects, that get decoded by the cpld
-EN: global enable
-SPARE: not in use yet
J19:
-SCLK, RCLK, SO, SI (standard, si not yet used, might be handy in future for things like reading out sid registers)
Status:
Two PCBs have been produced, one of them has all components placed.
The CPLD-design is still beta, but will be stable before too long (this is caused by size difficulties, maybe a bigger cpld in future versions)
Edit:
IC6 / Pin3 must be on VCC for reliable operation. This corection is the blue wire on the bottom side of the pcb.
Schematics:
Attachement MBHP_SID_V42_CPLD.pdf