You know you’re procrastinating when you find yourself organizing your breadboard wire. :P
That drawer I have is an gku™ Underdesk Keyboard Drawer under desk keyboard tray and storage AC1009.
Breadboard wire
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Category Archives: Electronics
Early Content #2: Scope Test | Learning Electronics In The Lab With Jay Jay
This post is part of my video blog and you can find more information about this video on this show’s homepage which is here.
You can support this channel on Patreon: patreon.com/JohnElliotV
This video is just me testing the operation and recording of my MSO5074 scope and my signal generator.
Thanks very much for watching! And please remember to hit like and subscribe!
Following is a product I use picked at random from my collection which may appear in my videos. Clicking through on this to find and click on the green affiliate links before purchasing from eBay or AliExpress is a great way to support the channel at no cost to you. Thanks!
EXAR XR2206 Signal Generator notes |
Let’s go shopping!
Early Content #1: Hello, World | Learning Electronics In The Lab With Jay Jay
This post is part of my video blog and you can find more information about this video on this show’s homepage which is here.
You can support this channel on Patreon: patreon.com/JohnElliotV
Just preparing my lab cameras. This video is a bit sketchy because I made some mistakes during recording. But it is what it is. Hi! :)
Thanks very much for watching! And please remember to hit like and subscribe!
Following is a product I use picked at random from my collection which may appear in my videos. Clicking through on this to find and click on the green affiliate links before purchasing from eBay or AliExpress is a great way to support the channel at no cost to you. Thanks!
Logitech Brio USB Camera |
Let’s go shopping!
Network v4
I have redone my computer network in its fourth (and final?) incarnation. Everything got redesigned from the ground up. You can see some of the (color coded!) cabling here:
The two switches on top (GREEN and ORANGE) support speeds up to 2.5 Gbps, whereas the bottom two switches (RED and BLUE) only support up to 1 Gbps. The white cables on the right are spares, they’re just auxiliary cables which have already been installed and are available if I need them in an emergency.
Samsung 990 PRO firmware version
I’m having an issue with my Samsung 990 PRO drive. Gonna try upgrading the firmware. Actually got myself a new computer just for the purpose. Figured I should start with knowing what the firmware version is presently. ChatGPT strikes again. Firmware version is 1B2QJXD7.
-------------------
Wed May 31 11:14:03 [bash:5.2.15 jobs:0 error:0 time:0]
jj5@charm:/home/jj5
$ ll /dev/disk/by-id/
total 0
drwxr-xr-x 2 root root 1.3K May 31 03:04 .
drwxr-xr-x 9 root root 180 May 30 08:45 ..
lrwxrwxrwx 1 root root 9 May 30 08:45 ata-DRW-24D5MT_KLCL6MF4200 -> ../../sr0
lrwxrwxrwx 1 root root 9 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D5506W -> ../../sdb
lrwxrwxrwx 1 root root 10 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D5506W-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D5506W-part9 -> ../../sdb9
lrwxrwxrwx 1 root root 9 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D8E3C9 -> ../../sda
lrwxrwxrwx 1 root root 10 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D8E3C9-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 May 31 03:04 ata-WDC_WD30EFRX-68EUZN0_WD-WMC4N0D8E3C9-part9 -> ../../sda9
lrwxrwxrwx 1 root root 9 May 30 08:45 md-name-charm:0 -> ../../md0
lrwxrwxrwx 1 root root 9 May 30 08:45 md-name-charm:1 -> ../../md1
lrwxrwxrwx 1 root root 9 May 30 08:45 md-uuid-9ef6fffa:0d37be5a:7842f20e:1319d620 -> ../../md1
lrwxrwxrwx 1 root root 9 May 30 08:45 md-uuid-f52df5c3:9aa1e0f1:8eab0df8:9808eaeb -> ../../md0
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-eui.00000000000000000026b768642eff55 -> ../../nvme1n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.00000000000000000026b768642eff55-part1 -> ../../nvme1n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.00000000000000000026b768642eff55-part9 -> ../../nvme1n1p9
lrwxrwxrwx 1 root root 13 May 30 09:57 nvme-eui.00000000000000000026b768642eff65 -> ../../nvme3n1
lrwxrwxrwx 1 root root 15 May 30 09:57 nvme-eui.00000000000000000026b768642eff65-part1 -> ../../nvme3n1p1
lrwxrwxrwx 1 root root 15 May 30 09:57 nvme-eui.00000000000000000026b768642eff65-part9 -> ../../nvme3n1p9
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-eui.00253842314123dd -> ../../nvme4n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.00253842314123dd-part1 -> ../../nvme4n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.00253842314123dd-part9 -> ../../nvme4n1p9
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-eui.6479a74fb0c004b7 -> ../../nvme2n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c004b7-part1 -> ../../nvme2n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c004b7-part2 -> ../../nvme2n1p2
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c004b7-part3 -> ../../nvme2n1p3
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c004b7-part4 -> ../../nvme2n1p4
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c004b7-part5 -> ../../nvme2n1p5
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-eui.6479a74fb0c00509 -> ../../nvme0n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c00509-part1 -> ../../nvme0n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c00509-part2 -> ../../nvme0n1p2
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c00509-part3 -> ../../nvme0n1p3
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c00509-part4 -> ../../nvme0n1p4
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-eui.6479a74fb0c00509-part5 -> ../../nvme0n1p5
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-KINGSTON_SNV2S2000G_50026B768642EFF5 -> ../../nvme1n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-KINGSTON_SNV2S2000G_50026B768642EFF5-part1 -> ../../nvme1n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-KINGSTON_SNV2S2000G_50026B768642EFF5-part9 -> ../../nvme1n1p9
lrwxrwxrwx 1 root root 13 May 30 09:57 nvme-KINGSTON_SNV2S2000G_50026B768642EFF6 -> ../../nvme3n1
lrwxrwxrwx 1 root root 15 May 30 09:57 nvme-KINGSTON_SNV2S2000G_50026B768642EFF6-part1 -> ../../nvme3n1p1
lrwxrwxrwx 1 root root 15 May 30 09:57 nvme-KINGSTON_SNV2S2000G_50026B768642EFF6-part9 -> ../../nvme3n1p9
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092 -> ../../nvme2n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092-part1 -> ../../nvme2n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092-part2 -> ../../nvme2n1p2
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092-part3 -> ../../nvme2n1p3
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092-part4 -> ../../nvme2n1p4
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100092-part5 -> ../../nvme2n1p5
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095 -> ../../nvme0n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095-part1 -> ../../nvme0n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095-part2 -> ../../nvme0n1p2
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095-part3 -> ../../nvme0n1p3
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095-part4 -> ../../nvme0n1p4
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-PNY_CS3140_1TB_SSD_PNY21242106180100095-part5 -> ../../nvme0n1p5
lrwxrwxrwx 1 root root 13 May 30 08:45 nvme-Samsung_SSD_990_PRO_2TB_S6Z2NJ0W215164J -> ../../nvme4n1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-Samsung_SSD_990_PRO_2TB_S6Z2NJ0W215164J-part1 -> ../../nvme4n1p1
lrwxrwxrwx 1 root root 15 May 30 08:45 nvme-Samsung_SSD_990_PRO_2TB_S6Z2NJ0W215164J-part9 -> ../../nvme4n1p9
lrwxrwxrwx 1 root root 9 May 30 08:45 wwn-0x5001480000000000 -> ../../sr0
lrwxrwxrwx 1 root root 9 May 31 03:04 wwn-0x50014ee604f5f467 -> ../../sda
lrwxrwxrwx 1 root root 10 May 31 03:04 wwn-0x50014ee604f5f467-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 May 31 03:04 wwn-0x50014ee604f5f467-part9 -> ../../sda9
lrwxrwxrwx 1 root root 9 May 31 03:04 wwn-0x50014ee65a4af2ed -> ../../sdb
lrwxrwxrwx 1 root root 10 May 31 03:04 wwn-0x50014ee65a4af2ed-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 May 31 03:04 wwn-0x50014ee65a4af2ed-part9 -> ../../sdb9
-------------------
Wed May 31 11:14:11 [bash:5.2.15 jobs:0 error:0 time:8]
jj5@charm:/home/jj5
$ sudo nvme smart-log /dev/nvme4
Smart Log for NVME device:nvme4 namespace-id:ffffffff
critical_warning : 0
temperature : 45°C (318 Kelvin)
available_spare : 100%
available_spare_threshold : 10%
percentage_used : 0%
endurance group critical warning summary: 0
Data Units Read : 2,237,856 (1.15 TB)
Data Units Written : 10,957,014 (5.61 TB)
host_read_commands : 48,079,050
host_write_commands : 119,766,894
controller_busy_time : 282
power_cycles : 31
power_on_hours : 23
unsafe_shutdowns : 16
media_errors : 0
num_err_log_entries : 0
Warning Temperature Time : 0
Critical Composite Temperature Time : 0
Temperature Sensor 1 : 45°C (318 Kelvin)
Temperature Sensor 2 : 49°C (322 Kelvin)
Thermal Management T1 Trans Count : 0
Thermal Management T2 Trans Count : 0
Thermal Management T1 Total Time : 0
Thermal Management T2 Total Time : 0
-------------------
Wed May 31 11:36:59 [bash:5.2.15 jobs:0 error:0 time:0]
root@charm:/home/jj5
# nvme id-ctrl /dev/nvme4 -H
NVME Identify Controller:
vid : 0x144d
ssvid : 0x144d
sn : S6Z2NJ0W215164J
mn : Samsung SSD 990 PRO 2TB
fr : 1B2QJXD7
rab : 2
ieee : 002538
cmic : 0
[3:3] : 0 ANA not supported
[2:2] : 0 PCI
[1:1] : 0 Single Controller
[0:0] : 0 Single Port
mdts : 9
cntlid : 0x1
ver : 0x20000
rtd3r : 0x30d40
rtd3e : 0x989680
oaes : 0x200
[31:31] : 0 Discovery Log Change Notice Not Supported
[27:27] : 0 Zone Descriptor Changed Notices Not Supported
[15:15] : 0 Normal NSS Shutdown Event Not Supported
[14:14] : 0 Endurance Group Event Aggregate Log Page Change Notice Not Supported
[13:13] : 0 LBA Status Information Notices Not Supported
[12:12] : 0 Predictable Latency Event Aggregate Log Change Notices Not Supported
[11:11] : 0 Asymmetric Namespace Access Change Notices Not Supported
[9:9] : 0x1 Firmware Activation Notices Supported
[8:8] : 0 Namespace Attribute Changed Event Not Supported
ctratt : 0x10
[19:19] : 0 Flexible Data Placement Not Supported
[15:15] : 0 Extended LBA Formats Not Supported
[14:14] : 0 Delete NVM Set Not Supported
[13:13] : 0 Delete Endurance Group Not Supported
[12:12] : 0 Variable Capacity Management Not Supported
[11:11] : 0 Fixed Capacity Management Not Supported
[10:10] : 0 Multi Domain Subsystem Not Supported
[9:9] : 0 UUID List Not Supported
[8:8] : 0 SQ Associations Not Supported
[7:7] : 0 Namespace Granularity Not Supported
[6:6] : 0 Traffic Based Keep Alive Not Supported
[5:5] : 0 Predictable Latency Mode Not Supported
[4:4] : 0x1 Endurance Groups Supported
[3:3] : 0 Read Recovery Levels Not Supported
[2:2] : 0 NVM Sets Not Supported
[1:1] : 0 Non-Operational Power State Permissive Not Supported
[0:0] : 0 128-bit Host Identifier Not Supported
rrls : 0
cntrltype : 1
[7:2] : 0 Reserved
[1:0] : 0x1 I/O Controller
fguid : 00000000-0000-0000-0000-000000000000
crdt1 : 0
crdt2 : 0
crdt3 : 0
nvmsr : 0
[1:1] : 0 NVM subsystem Not part of an Enclosure
[0:0] : 0 NVM subsystem Not part of an Storage Device
vwci : 0
[7:7] : 0 VPD Write Cycles Remaining field is Not valid.
[6:0] : 0 VPD Write Cycles Remaining
mec : 0
[1:1] : 0 NVM subsystem Not contains a Management Endpoint on a PCIe port
[0:0] : 0 NVM subsystem Not contains a Management Endpoint on an SMBus/I2C port
oacs : 0x17
[10:10] : 0 Lockdown Command and Feature Not Supported
[9:9] : 0 Get LBA Status Capability Not Supported
[8:8] : 0 Doorbell Buffer Config Not Supported
[7:7] : 0 Virtualization Management Not Supported
[6:6] : 0 NVMe-MI Send and Receive Not Supported
[5:5] : 0 Directives Not Supported
[4:4] : 0x1 Device Self-test Supported
[3:3] : 0 NS Management and Attachment Not Supported
[2:2] : 0x1 FW Commit and Download Supported
[1:1] : 0x1 Format NVM Supported
[0:0] : 0x1 Security Send and Receive Supported
acl : 7
aerl : 3
frmw : 0x16
[5:5] : 0 Multiple FW or Boot Update Detection Not Supported
[4:4] : 0x1 Firmware Activate Without Reset Supported
[3:1] : 0x3 Number of Firmware Slots
[0:0] : 0 Firmware Slot 1 Read/Write
lpa : 0x2f
[6:6] : 0 Telemetry Log Data Area 4 Not Supported
[5:5] : 0x1 LID 0x0, Scope of each command in LID 0x5, 0x12, 0x13 Supported
[4:4] : 0 Persistent Event log Not Supported
[3:3] : 0x1 Telemetry host/controller initiated log page Supported
[2:2] : 0x1 Extended data for Get Log Page Supported
[1:1] : 0x1 Command Effects Log Page Supported
[0:0] : 0x1 SMART/Health Log Page per NS Supported
elpe : 63
[7:0] : 63 (0's based) Error Log Page Entries (ELPE)
npss : 4
[7:0] : 4 (0's based) Number of Power States Support (NPSS)
avscc : 0x1
[0:0] : 0x1 Admin Vendor Specific Commands uses NVMe Format
apsta : 0x1
[0:0] : 0x1 Autonomous Power State Transitions Supported
wctemp : 355
[15:0] : 82°C (355 Kelvin) Warning Composite Temperature Threshold (WCTEMP)
cctemp : 358
[15:0] : 85°C (358 Kelvin) Critical Composite Temperature Threshold (CCTEMP)
mtfa : 0
hmpre : 0
hmmin : 0
tnvmcap : 2,000,398,934,016
[127:0] : 2,000,398,934,016
Total NVM Capacity (TNVMCAP)
unvmcap : 0
[127:0] : 0
Unallocated NVM Capacity (UNVMCAP)
rpmbs : 0
[31:24]: 0 Access Size
[23:16]: 0 Total Size
[5:3] : 0 Authentication Method
[2:0] : 0 Number of RPMB Units
edstt : 35
dsto : 0
fwug : 0
kas : 0
hctma : 0x1
[0:0] : 0x1 Host Controlled Thermal Management Supported
mntmt : 318
[15:0] : 45°C (318 Kelvin) Minimum Thermal Management Temperature (MNTMT)
mxtmt : 356
[15:0] : 83°C (356 Kelvin) Maximum Thermal Management Temperature (MXTMT)
sanicap : 0x60000003
[31:30] : 0x1 Media is not additionally modified after sanitize operation completes successfully
[29:29] : 0x1 No-Deallocate After Sanitize bit in Sanitize command Not Supported
[2:2] : 0 Overwrite Sanitize Operation Not Supported
[1:1] : 0x1 Block Erase Sanitize Operation Supported
[0:0] : 0x1 Crypto Erase Sanitize Operation Supported
hmminds : 0
hmmaxd : 0
nsetidmax : 0
endgidmax : 1
anatt : 0
anacap : 0
[7:7] : 0 Non-zero group ID Not Supported
[6:6] : 0 Group ID does change
[4:4] : 0 ANA Change state Not Supported
[3:3] : 0 ANA Persistent Loss state Not Supported
[2:2] : 0 ANA Inaccessible state Not Supported
[1:1] : 0 ANA Non-optimized state Not Supported
[0:0] : 0 ANA Optimized state Not Supported
anagrpmax : 0
nanagrpid : 0
pels : 0
domainid : 0
megcap : 0
sqes : 0x66
[7:4] : 0x6 Max SQ Entry Size (64)
[3:0] : 0x6 Min SQ Entry Size (64)
cqes : 0x44
[7:4] : 0x4 Max CQ Entry Size (16)
[3:0] : 0x4 Min CQ Entry Size (16)
maxcmd : 256
nn : 1
oncs : 0x55
[8:8] : 0 Copy Not Supported
[7:7] : 0 Verify Not Supported
[6:6] : 0x1 Timestamp Supported
[5:5] : 0 Reservations Not Supported
[4:4] : 0x1 Save and Select Supported
[3:3] : 0 Write Zeroes Not Supported
[2:2] : 0x1 Data Set Management Supported
[1:1] : 0 Write Uncorrectable Not Supported
[0:0] : 0x1 Compare Supported
fuses : 0
[0:0] : 0 Fused Compare and Write Not Supported
fna : 0x7
[3:3] : 0 Format NVM Broadcast NSID (FFFFFFFFh) Supported
[2:2] : 0x1 Crypto Erase Supported as part of Secure Erase
[1:1] : 0x1 Crypto Erase Applies to All Namespace(s)
[0:0] : 0x1 Format Applies to All Namespace(s)
vwc : 0x7
[2:1] : 0x3 The Flush command supports NSID set to FFFFFFFFh
[0:0] : 0x1 Volatile Write Cache Present
awun : 1023
awupf : 0
icsvscc : 1
[0:0] : 0x1 NVM Vendor Specific Commands uses NVMe Format
nwpc : 0
[2:2] : 0 Permanent Write Protect Not Supported
[1:1] : 0 Write Protect Until Power Supply Not Supported
[0:0] : 0 No Write Protect and Write Protect Namespace Not Supported
acwu : 0
ocfs : 0
[1:1] : 0 Controller Copy Format 1h Not Supported
[0:0] : 0 Controller Copy Format 0h Not Supported
sgls : 0
[15:8] : 0 SGL Descriptor Threshold
[1:0] : 0 Scatter-Gather Lists Not Supported
mnan : 0
maxdna : 0
maxcna : 0
subnqn : nqn.1994-11.com.samsung:nvme:990PRO:M.2:S6Z2NJ0W215164J
ioccsz : 0
iorcsz : 0
icdoff : 0
fcatt : 0
[0:0] : 0 Dynamic Controller Model
msdbd : 0
ofcs : 0
[0:0] : 0 Disconnect command Not Supported
ps 0 : mp:9.39W operational enlat:0 exlat:0 rrt:0 rrl:0
rwt:0 rwl:0 idle_power:- active_power:-
active_power_workload:-
ps 1 : mp:9.39W operational enlat:0 exlat:200 rrt:1 rrl:1
rwt:1 rwl:1 idle_power:- active_power:-
active_power_workload:-
ps 2 : mp:9.39W operational enlat:0 exlat:1000 rrt:2 rrl:2
rwt:2 rwl:2 idle_power:- active_power:-
active_power_workload:-
ps 3 : mp:0.0400W non-operational enlat:2000 exlat:1200 rrt:3 rrl:3
rwt:3 rwl:3 idle_power:- active_power:-
active_power_workload:-
ps 4 : mp:0.0050W non-operational enlat:500 exlat:9500 rrt:4 rrl:4
rwt:4 rwl:4 idle_power:- active_power:-
active_power_workload:-
-------------------
System freeze
My backup Kubuntu workstation began freezing shortly after boot recently. The problem was recurrent for a week or so and then I just switched the damn thing off. Have picked this up again recently to try and fix, because I would like to make use of this machine’s disks.
I ran MemTest86, and that surfaced no errors. Seems as though the RAM is okay and probably the CPU too.
The first thing I tried after the memory test was to remove the WD Blue 250GB SATA SSD M.2 which was in use as a ZFS cache. And this seems to have fixed the problem! Can’t be sure yet, but so far so good. Will continue to keep an eye on things…
Here are some photos for those playing along at home:
RAM
I learned a few things about RAM today. Things began with the realisation that a CPU can read 32GB of RAM (e.g. all of it) in about 10 seconds. That surprised me at first, and then I thought about it (for the first time ever, not usually a big fan of thinking, can lead to discomfort).
Then I learned that DDR4 has a 64-bit data bus whereas DDR5 has a 128-bit data bus.
And then I learned that today’s SDRAM used to be asynchronous DRAM.
TI MSP430
Reading about the TI MSP430 microcontroller. A pretty nifty looking device. It is referenced in Zen and the Forth Language: EFORTH for the MSP430 from Texas Instruments.
The T2 Tile Project
Today I discovered The T2 Tile Project. Looks pretty cool! It’s a whole new approach to computing with a focus on robustness.
The project is being run by David Ackley.
Eurorack synths
Here’s a whole rabbit hole: eurorack synths.