So, I have set up Enlightenment a bit and am transferring to ssd now with rsync.
I marginally prefer Enlightenment, although it only offers an en-US keyboard. I have no alternative. That'e fine for the Excited States, but other places exist and people live in them. Enlightenment doesn't appear to have qt5 installed. Doing a quick check on slarm64.org, I see a patch for qt-5.12.3, but no qt5 source or package.

But I presume you needed qt5 to build vlc? Have you packages or am I compiling?

why, all packages are identical and are located in the same place and in slackware.

Thanks. Bookmarked that link.

As for the extremely slow problem, 99% it's the usb key. Just watching the sdcard boot essentially the same kernel, it's clear. Hdparm times it at 22.85MB/S in a USB3, but 114MB/S in a usb2 socket.
As for the "Read only root drive" problem: I'm pretty sure I've solved it. It's sda2 on the ssd.
I'm posting in Hardware about the drive issues.

Yours, and other images have

1. sda1=/boot ≤ 256Megs, vfat.
2. sda2=root, usually just larger than the install.

On my ssd, I enlarged sda2 with parted, and resize2fs, and added another sda3=/home, nearly 200G of which 126G is media. I was trying to avoid touching that, but it looks like I'd be better off wiping it.

Said he, confidently. Now I just don't know

If you remember, I have an sdcard which boots the XFCE image on kernel 5.15.5. I couldn't get the ssd boot that XFCE image, as it wouldn't mount sda2 read/write. I also had a rash of hardware issues around then. So I replaced my usb key and configured it as sda to boot the Enlightenment image with kernel 5.15.10. I got all the reconfiguration sorted on the usb key and it mounted sda2 just fine. I Transferred the same files with 'rsync -avc --delete' to the ssd. That wouldn't mount sda2 read/write, and I took it to be a partition problem on the ssd. Now I had made the partitions sda1 & sda2 with a dd of some image (slackware Arm 32bit?), and had then gone at sda2 with resize2fs, so I guessed that was my problem.

Finally, I transferred the 120G of media on sda3 to a backup disk, & wiped all partitions on the ssd. I made a backup of the new USB key (booting in the RazPi). I remade partitions with fdisk, changing the partition sizes in case I'd overwrite the same spot (just in case). Then I copied back my 120G of media, copied back my Enlightenment image. This morning, I booted the RazPi, but I had a read-only sda2 I diffed files between ssd & usb key, but naturally, they were identical.

Now my pc can write to any partition of the ssd no problem. I'm left wondering why the kernel can't mount sda2 in this particular ssd, whereas the same kernel can write to sda3, which is also ext4.

In fact on runlevel 3, if I hit Alt_F2, log in, and enter the command root mounts rw, and all is well. So why does it mount sda2 on a terminal and not on bootup? Have we a little jiggery-pokery going on here?

show your fstab and mount output.

bring to mind.

The fstab is your formatI tried the following:

1. Line 324 of rc.S has the line
   Code:

   /sbin/mount -f -w /

   which I commented out and replaced with
   Code:

   /sbin/mount -f -o remount,rw /

   but that made no change, so I restored the original.
2. fsck on / which of course was fine.
3. When it comes up in level 4, it's trying to boot X on tty1. Every other tty wants to add a user. I left that useradd script hanging and pressed Ctrl_C on tty3, logged in as root and tried remounting / with the standard remount line (above). Then I checked as root the output of the 'mount' command, which clearly showed sda2 on / as rw. But 'touch file' in root's homedir resulted in a "Read Only filesystem' error'
4. Removed the "errors=remount,ro" from the / mount options in /etc/fstab. No change.
5. Checked the usb key again, in case my memory was playing tricks. It boots fine, mounts / rw and works.

I have a usb key with identical files which boots with / rw. The only things left are the usb disk & caddy, but this makes no sense at all. It has one of those usb3 <-->sata converters. Changing that will have to wait for the Saturnalia (Xmas) when/if my son has a free moment to change the caddies for me. Christmas is not a thing here, we don't go for it.

So I think I have cleared Slarm64 of blame. That being the case, I'll mark this solved again and post this issue on the hardware forum. Thanks for the help.

Still running on an sdcard but chasing away slowly. I swapped usb disk cases, but that changed nothing. So I started at the mount command of /, and found that the checks done in rc.S are singularly unsuited to the RazPi. Many tests are unnecessary, and something is upsetting the works such that the mount command in rc.S in not mounting. Here is where slavish compatibility to an x86 pc/server breaks down.

For instance, switching to runlevel 3, and logging in as root, sometimes succeeds. Sometimes adding '-f' succeeds. But adding the '-f' to / rc.S doesn't work.

So, I'm going to play away at my leisure with a copy of rc.S, hacking it to see if I can simplify it without sacrificing anything in the mount department (lines 250-300 or thereabouts).

everything in rc.S works correctly on any of my boards, if you make changes during the next update, you will have to make changes again.

Definitely doesn't here. Not developing your OS here, but investigating.
It works on a usb key looking at me, but doesn't work in a perfectly fine ssd which mounted / rw (the same partition) under Buster & Bullseye, but not under Slackware. The fixer in me is curious, that's all. I'm not considering updating yet.

try to transfer through a script transfer-to-disk

I did that. Using the mmc card in my Pi, I stuck a usb key in and ran it. First problem was that it needed runlevel 2 or lower, but runlevel 2 isn't used on slackware. I changed /etc/inittab for runlevel 1, and ran the script.

I got to the stage where it started copying and left it. The progress bar stayed at 0% on the screen, but after lunch it had exited. I restored runlevel on the mmc, & rebooted on the disk. The partitioning was A-OK. /boot was empty, which was embarassing. The only populated directory was etc/, with 22 Megs. Root uses a gig of disk space but I can find no sizable files, not even hidden ones.The rest are empty. I think rsync will do for now, thanks.

why not

Init 2 isn't assigned in Slackware, according to /etc/inittab.

it only says that no actions are taking place, so the system goes to level 2.
check

Never mind. I was underwhelmed with the script anyhow, because I ran it in runlevel 1 which is "under 2" as it requires. I'm still not mounting / on the ssd (XFCE image on it now). But I noticed I don't think I see this warning. and because the fonts are so miniscule and the init process so verbose, I can't be sure. So I've added a bit to check it's running that line. But as usual, writing on the pc, while fixing the Pi. I'll update with any news.