cwc

I.S. 1050 Plate Enhancement Manual.pdf

I think the Happy Archiver software was an "all in one" solution uploading an Archiver emulator to the Happy hardware as well as the Archiver 1.1 software into the computer. Otherwise, you had to load the emulator (attached above by @Larry, which is the one I think everyone says actually works) and then the Archiver software separately.

https://archive.org/details/ArchiverEditor https://archive.org/details/Atari_Original_Archiver_Operating_Instructions

https://archive.org/details/a8b_Happy_1050_Chip_Archiver_Editor_The_v1.1_19xx_Fox

In case you haven't found the manual: http://blog.3b2.sk/igi/post/Hyper2b-XF-10-MANUAL.aspx

If I am getting this right from another thread (happy to be corrected), the firmware on your XF551 without U6 will be on the P8050H processor U1. I assume you can install a socket and EPROM in U6 (as you have done) then change the jumper from the S3 to S4 position and that should do it. See: https://forums.atariage.com/topic/338300-atari-xf-551-roms/?do=findComment&comment=5308127

Regarding the jumpers on the Controller Board: "In the factory set configuration the three position switch of the CONTROLLER will affect the write protect until a software protect/unprotect command is issued, such as from the program options menu of the VARP SPEED SOFTVARE After the protect/unprotect command is issued the three position switch has no effect until that mode is reset. Therefore, in this mode the software has priority over the manual switch. In the first alternate configuration all three factory jumpers are cut and jumpers are installed in the three adjacent positions. In this mode the software command has effect only when the three position switch is in the NORMAL or down position Thus, in this alternate configuration the manual switch setting has priority over the software command. In the last alternate configuration the center one of the three factory jumpers is cut, leaving the other two original jumpers. In this mode the manual switch and the disk notch have no effect. Disk writing is prohibited until the unprotect command is issued through software. This can prevent unauthorised writing to disks if only you know how to execute the unprotect command."

Happy 1050 Controller Installation and Usage Instructions.pdf

U21 (3086)?

Information on mod here.

Worth also bearing in mind that Happy drives will show as Lazer Drives in the Lazer software so the only way to find out if you've got a Happy (or clone) is to put the drive through its full paces using the Happy Software. To add to the complexity, there was a hacked version of the Happy Software for the Lazer (on @E474's Lazer thread) - so don't use that for testing!

Looks like you were checking the drive with Happy v5.1 software which I think will have been for the 810 disk drive and may not recognise a 1050 Happy. Suggest you try with a later version of the software (v6.6 or higher) just to make sure. Atr images are here.

Full description in Happy Computers Flyer December 1986 on Internet Archive here.